ASSET study on impact of wooden buildings on climate, embodied energy and GHG-emissions.
Date: 2020-12-04
Institutions: Directorate-General for Energy
Subjects: building, building materials, climate, energy efficiency, greenhouse gas, materials technology, reduction of gas emissions, wood product

ASSET Study on 

Impact of Wooden Buildings on 

Climate, Embodied Energy        

and GHG-Emissions 

mmmll 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

AUTHORS  

Kjell Bettgenhaeuser (Guidehouse) 

Gereon Rupp (Guidehouse) 

Tom Berg (Guidehouse) 

Annemarie Kerkhof (Guidehouse) 

Andreas Hermelink (Guidehouse) 

EUROPEAN COMMISSION 

Directorate-General for Energy 
Directorate for Renewables, Research and Innovation, Energy Efficiency 
Unit: C2 – Innovation, clean technologies and competitiveness 

Contact: Eric Lecomte 

E-mail: Eric.LECOMTE@ec.europa.eu 

European Commission 
B-1049 Brussels 

June 2020  I  2 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Legal Notice 
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Luxembourg: Publications Office of the European Union, 2020 

© European Union, 2020  

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PDF   ISBN 978-92-76-26949-6   doi: 10.2833/53479   MJ-04-20-678-EN-N 

June 2020  I  3 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

About the ASSET project 
The ASSET Project (Advanced System Studies for Energy Transition) aims at providing 
studies in support to EU policy making, research and innovation in the field of energy. 
Studies  are  in  general  focussed  on  the  large-scale  integration  of  renewable  energy 
sources  in  the  EU  electricity  system  and  consider,  in  particular,  aspects  related  to 
consumer  choices,  demand-response,  energy  efficiency,  smart  meters  and  grids, 
storage, RES technologies,  etc. Furthermore, connections between the electricity grid 
and  other  networks  (gas,  heating  and  cooling)  as  well  as  synergies  between  these 
networks are assessed. 

The ASSET studies not only summarize the state-of-the-art in these domains, but also 
comprise  detailed  qualitative  and  quantitative  analyses  on  the  basis  of  recognized 
techniques  in  view  of  offering  insights  from  a  technology,  policy  (regulation,  market 
design) and business point of view. 

Disclaimer 
The  study  is  carried  out  for  the  European  Commission  and  expresses  the  opinion  of 
the organisation having undertaken them. To this end, it does not reflect the views of 
the European Commission, TSOs, project promoters and  other  stakeholders involved. 
The  European  Commission  does  not  guarantee  the  accuracy  of  the  information  given 
in the study, nor does it accept responsibility for any use made thereof. 

Authors 
This study has been developed as part of the ASSET project by Guidehouse. 

Lead Author: Kjell BETTGENHAEUSER (Guidehouse) 
Authoring  Team:  Gereon  RUPP  (Guidehouse),  Tom  BERG  (Guidehouse),  Annemarie 
KERKHOF (Guidehouse), Andreas HERMELINK (Guidehouse) 

June 2020  I  4 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
  
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Table of Contents 

About the ASSET project .................................................................................... 4 
Disclaimer ........................................................................................................ 4 
Table of Contents .............................................................................................. 5 
Executive summary ........................................................................................... 7 
Introduction .....................................................................................................13 
Background ...................................................................................................13 
Goal of the Study ...........................................................................................13 
Overview of Methodology ................................................................................13 
LIFE CYCLE ASSESSMENT OF INDIVIDUAL BUILDINGS ..........................................16 
Key Findings of LCA on individual Building Level ................................................16 
Methodology - Introduction to LCA ...................................................................16 
General Concept of LCA ...............................................................................17 
Relevant Standards .....................................................................................18 
EU Level(s) Framework ................................................................................22 
Stage I: Goal and Scope of LCA .......................................................................24 
Reference Buildings and Construction Variants ................................................24 
Energy Balances .........................................................................................25 
Stage II: Lifecycle Inventory - Mass and Material Balances .................................25 
Stage III: Impact Assessment .........................................................................27 
Single-Family House ....................................................................................27 
Multi-Family House ......................................................................................28 
Office Building ............................................................................................29 
Stage IV: Evaluation and Interpretation ............................................................30 
Impact of Wooden Buildings on the EU Building Sector ..........................................31 
Key Findings on EU Building Sector Level ..........................................................31 
Methodology for EU Building Sector Scenarios ...................................................31 
Determination of the Baseline .........................................................................32 
New Building Rates and Wood Market Shares .................................................32 
Replaced Building Construction Types ............................................................33 
Baseline GHG Emissions ...............................................................................33 
Baseline Wood Demand ...............................................................................35 
Quantification of the Potential of EU's Forests ....................................................36 
Carbon Sequestration in Forests and Wood Products .......................................36 
Wood Harvesting Scenarios ..........................................................................37 
Forestry Sector Impacts ...............................................................................38 
Upper limit and bandwidth of GHG Emission Reduction .......................................41 
Ad Hoc GHG Savings Potential ......................................................................41 
Additional  Constraints  and  Boundary  Conditions  for  the  uptake  of  Wooden 
Buildings ....................................................................................................42 
Realistic  Pathway:  Additional  GHG  Savings  Through  an  Uptake  of  Wooden 
Buildings ....................................................................................................44 
Discussion ....................................................................................................51 
EU Policy Analysis and Recommendations ............................................................53 
Key Policy Recommendations ..........................................................................53 
Overview of the current EU Building Regulation .................................................53 
Identify Options to Promote Wood Construction .................................................54 
Indirect wood construction policies ................................................................55 
Direct Wood Construction Policies .................................................................55 
Discussion ....................................................................................................56 
Conclusions .....................................................................................................58 
Further Research Questions ...............................................................................59 
References.......................................................................................................61 

June 2020  I  5 

 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Annex I - Analysis of individual Buildings: Detailed Input and Outputs.....................64 
Reference Buildings (LCA stage I) ....................................................................64 
Reference Building “Single-Family House” ......................................................64 
Reference Building “Multi-Family House” ........................................................65 
Reference Building “Office” ...........................................................................66 
Building Construction Variants and Materials (LCA stage I) ..................................68 
Basement ..................................................................................................68 
Energy Balance (LCA stage I) ..........................................................................81 
Mass Balance (LCA stage II) ............................................................................81 
LCA Impact Assessment Details (LCA stage III) .................................................83 
Annex II – Impact of Wooden Building on EU Building Sector – Details ....................85 
Methodology – The Navigant BEAM² Model ........................................................85 
EU Forest Sector ............................................................................................89 
Carbon Sequestration in Forests and Wood Products .......................................90 
Wood Harvesting Scenarios ..........................................................................91 
Forestry Sector Impacts ...............................................................................94 

June 2020  I  6 

 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Executive summary 
This study determines the greenhouse gas reduction potential in the European building 
sector  by  using  wood  as  the  main  construction  material  for  new  buildings  instead  of 
mineral  materials  such  as  brick,  stone,  and  concrete.  The  study’s  conclusions  are 
summarised in the following   five key findings for the EU28: 

1.  On an individual building level, >90% of greenhouse gas  emissions can be 

saved for manufacturing and construction currently when using wood as the main 
construction material instead of an average mix of mineral materials – without 
considering the CO2-storage effect of wood. 

2.  62 Mt of greenhouse gas emissions can be avoided in the year 2050 and 827 Mt 
cumulatively until 2050 through the substitution of mineral materials in new 
buildings if the current wood market share for new buildings steadily increases 
from 5.5% in 2020 to 75% by 2050 (with the assumption of current energy mix 
and processes).  

3.  The EU28 Forest has significant potential to provide for additional wood use in 

the buildings sector. Recent studies quantify the additional capacity between 60 - 
235 Mm3 per year (on top of the current annual  wood use - not only in buildings - 
with 700-800 Mm³). For 75% of the wood market share approx. 90 Mm³ would be 
required. However, even if wooden buildings would reach a 75% market share, 
the forest would still remain a net-sink.  

4.  In addition to the substitution effect, as a building material, wood can store up 

to 83 Mt of CO2 in the form of carbon in the year 2050 (compared to approx. 6 Mt 
of CO2 today) in the form of carbon. Over the entire time span until 2050, would 
buildings could accumulate a total of 1,112 Mt and continue to store it for a long 
time.  This is quite significant compared to the GHG emissions of current buildings 
for the use phase, equalling approx. 650 Mt CO2_eq per year.  

5.  The storage effect of wooden buildings could be maintained for a long time, as 

long as disposed or burned wood  is replaced with new wood products. In this way 
the “carbon sink” of the building sector would eventually saturate, but the 
carbon removed from the atmosphere would be permanent. However, wood 
should be reused as often as possible as material to avoid the carbon content to 
be released. 

6.  In total, the substitution and storage effect account for up to 145 Mt in 2050 and 

1939 Mt cumulated until 2050. 

7.  The emission trading system and environmental taxes are the central EU policy 
instruments regarding the promotion of wood in the construction sector, but 
they need to be aligned with other supporting policies. 

June 2020  I  7 

 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

New  buildings  across  the  EU  must  comply  with  the  nearly  zero-energy  buildings 
(nZEBs) concept within the EPBD [EPBD, 2017]. As a result, the energy use and GHG 
emissions that occur during the use phase  of new buildings is decreasing. This study 
shows  that  GHG  emissions  from  the  use  phase  of  typical  new  standard  residential 
buildings  can  decrease  towards  levels  of  20%-40%  when  very  energy  efficient 
buildings  with  heat  pumps  are  constructed  with  mineral  materials.  This  shows  that 
embodied  energy  for  new  buildings  are  very  relevant  in  the  overall  life  cycle  of  a 
building, while the challenge is to significantly reduce it.  

This study conducts a life cycle analysis for individual building and construction 
types,  which  determines  the  total  global  warming  potential  in  CO2-equivalent 
greenhouse gas emissions over the entire life cycle of the building. The life cycle of a 
building includes the operation and the manufacturing of the materials as well as the 
construction of the building  – and ideally also the later reuse, recycling, and disposal 
of  the  materials.  Timber  construction  types  such  as  solid  wood  and  wood  frame  are 
considered  main  construction  variants  for  buildings,  whereas  brick,  sand-limestone, 
reinforced concrete, and cellular concrete represent alternative mineral constructions. 
These  construction  types  are  typically  applied  for  new  buildings  of  single-family 
houses,  multifamily  houses,  and  office  buildings.  The  main  output  of  the  life  cycle 
analysis  is  that  the  manufacturing  phase  of  mineral  building  variants  creates 
significantly more greenhouse gas emissions than it does for wooden building variants 
(see  Figure  1  –  where  a  concrete  basement  is  assumed  for  all  variants).  The  use-
phase of all buildings is the same, therefore it is not considered here. Since the carbon 
content of wood (storage effect) is also accounted for, there are even negative values 
for  the  CO2-Storage  of  wooden  buildings.  Later  in  the  disposal  phase  the  CO2  is 
released  again  (by  default  thermal  usage  of  wood),  if  the  wood  is  not  reused  (which 
would be the best option). However, also considering the recycling potential,1 the solid 
wood  variant  has  the  lowest  global  warming  potential  with  nearly  zero  (2  t  CO2_eq), 
followed by the wooden frame construction (41 t CO2_eq). If the wood could be reused 
again and again for a very long period, it would mean long-term carbon storage.  This 
should be the preferred option (see also  Figure 21 in chapter 3.3 on the total carbon 
sink  of  the  forest  and  its  wooden  products).  The  mineral  construction  variants  were 
much  higher  and  do  not  differentiate  significantly  from  each  other  (344  -  390  t 
CO2_eq).  

1  The  recycling  potential  considers  further  usage  of  the  material  in  buildings/products  instead  of  default 
usage in the disposal phase (thermal combustion for wood or recycled debris for concrete/stone). 

June 2020  I  8 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 1: Waterfall Diagram on Global Warming Potential (GWP) over the Life Cycle of 
MFH Construction Variants without Use Phase (Source: Legep Modelling) 

Based on the analysis of individual reference buildings, a bottom-up analysis is used 
in  a  second  step  to  upscale  the  effects  to  the  European  building  sector  with 
increasing  shares  of  wooden  buildings.  For  this  task,  the  analysis  includes  the  Built-
Environment-Analysis-Model  (BEAM²)  to  determine  the  total  new  building  activity 
across Europe in 2020 and in a forecast towards 2050. In this context, the availability 
of  wood  from the European Forests is also  considered (chapter 3), where at least 60 
million m³ are available in addition to the current usage.  

Based  on  a  recent  Navigant  study  [Esser  et  al.,  2019]  on  the  new  building  and 
renovation  activity  across  the  EU,  this  report  uses  an  average  new  building  rate  of 
0.7%  for  residential  and  1.1%  for  non-residential  buildings  for  the  analysis.  The 
current  wood  building  market  share  in  the  EU  can  be  approximated  with  5.5%  of  all 
new buildings in 2020. An average growth  rate of wooden buildings of 3% p.a. since 
2000  leads  to  the  definition  of  the  baseline  pathway  (see  Figure  2).  Thus,  a  wood 
market share of 13% for residential and the majority of non-residential buildings2 can 
be achieved by 2050. A more ambitious wood market share leads to the  upper limit 
pathway.  Here  the  market  share  is  growing  steadily  towards  15%  p.a.  and  then 
decreases  again  when  the  wood  market  share  reaches  its  assumed  maximum.  The 
yearly  increase  of  the  wood  market  share  is  ambitious,  but  also  realistic.3  By  this 
ambitious definition, the wood market share ends up at 75% of all new buildings. 

2  Only  3/4  of  the  heated  non-residential  building  stock  can  be  approximated  with  the  office  reference 
building building, the reminding 1/4 of heated floor area in non-residential buildings are not covered. 
3  Similar  developments  have  been  observed  and  also  assumed  for  modelling  in  a  study  of  heat  pump 
potentials with the EU market [Bettgenhäuser et al., 2013]. 

June 2020  I  9 

241344367390Solid Wood MFHWood Frame MFHBrick MFHSand-Limestone MFHReinforcedConcreteMFHGWP (t CO2_eq)Building lifecycle information according to EN 15804Manufacturing/construction (phase A), Retrofit (phase B2-5), End of life (phase C), Recycling Potential (phase D)Increase of GWPDecrease of GWP 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 2: New buildings in the EU (residential and non-residential) and baseline/upper 
limit for wood market share (Source: BEAM²) 

Based  on  this  development  for  wooden  buildings,  the  savings  in  greenhouse  gas 
emissions are calculated over the life cycle for the buildings. Figure 3 summarises the 
greenhouse gas emissions of conventional building materials versus wood over the life 
cycle (without use phase) for new buildings in the EU28 for the baseline pathways and 
the upper limit pathway in steps for 2020, 2030, 2040, and 2050.  

Figure 3: GWP of conventional building materials vs. wood over the Life Cycle for new 
buildings in the EU (Source: Legep & BEAM² Modelling) 

June 2020  I  10 

4,90,96,811,71,31,99,342,41,76,712,973,72,411,6-5,3-4,4-13,6-83,6-11,2-71,9-100-80-60-40-20020406080100BaseUpperBaseUpperBaseUpperBaseUpperBaseUpperBaseUpperBaseUpperBaseUpperBaseUpperMine-ralWoodWood-netMineralWoodWood-netMineralWoodWood-netMineralWoodWood-netGWP (Mt CO2_eq)GWP of Conventional Building Materials vs. Wood for New Buildings in the EUCO2 storage in woodGHG over LifecycleNet-effect-145 Mt2020203020402050Legend:Wood: GWPof buildings towards a 75% wood market share for new buildings (5.5% in 2020, 13% by 2030, 45% by 2040, 75% by 2050)Mineral: Corresponding GWP of the same buildings as "wood", but in mineral construction Wood-net: Net GWP of wooden buildingsBase: BaselineUpper: Upper limit pathway-62 MtPositive GHG Emissions (GWP)Negative GHG Emissions (GWP) 
 
 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Mineral  buildings  always  end  up  with  a  significant  positive  global  warming  potential 
over  their  lifetime  (e.g.  73.7  Mt  in  2050  for  the  upper  limit  pathway  =  75%  of  new 
buildings).  Wooden  buildings  show  lower  positive  emissions  for  manufacturing, 
retrofitting,  disposal,  and  end-of-life  cycle  (e.g.  11.6  Mt  in  2050),  but  negative 
emissions if the CO2 stored in wood is taken into account (e.g. -83.6 Mt in 2050).  

Figure 4: GWP for Substitution and Storage Effect of wood vs. mineral building 

material for new buildings in the EU28 – upper limit                                                       

(Source: Legep & BEAM² Modelling) 

The overall net-effect of wooden buildings is  62 Mt in 2050 or even 145 Mt (if the 
CO2  stored  in  wood  is  accounted  for  and  remains  removed  from  the  atmosphere  – 
meaning  wood  is  reused  where  possible  and  replaced  by  fresh  wood  if  reuse  is  not 
possible).  This  is  shown  in  Figure  4,  which  displays  the  CO2  storage  effect  and  the 
substitution effect of wooden buildings for the upper limit pathway (75% wood market 
share  until  2050).  These  numbers  (62  Mt  and  145  Mt,  respectively)  for  the  life  cycle 
(without  use  phase)  of  the  building  are  significant  compared  to  the  current  GHG 
emissions  for  the  EU  building  sector  (use  phase  of  buildings  only),  at  approximately 
650  Mt  p.a.  A  “shifting  baseline”  for  mineral  and  wooden  buildings  (e.g.  decreasing 
carbon footprint of electricity and energy supply) would affect the mineral construction 
variants more than the wooden construction variants due to a higher energy demand 
in the production process for mineral variants.  
Approximately  90  Mm³  of  additional  wood  resources  would  be  required  for  the 
upper  limit  pathways  by  2050  for  solid  wooden  constructions  (using  mainly  cross-
laminated  timber  [CLT]),  WF  constructions  (using  mainly  glulam  and  oriented  strand 
boards  [OSB])  and  wooden  insulation  (wood  fibre  insulation  boards  ([WFIB]  and 
medium density fibre [MDF]), see Figure 5. This amount is reasonable as studies show 
the upper limit of additional sustainable wood resources from EU forests with a range 
of  60–235  Mm3  per  year  by  2030  (see  chapter  3),  and  more  wood  could  be  made 
available for saw-wood and use as glulam or cross-laminated timber from the existing 
use-cascade.  

June 2020  I  11 

-160-140-120-100-80-60-40-200GWP (Mt CO2_eq)Total Mt CO2_eq -Substitution Effect and Storage Effect -upper limitStorage Effect (upper limit)Substitution Effect (upper limit)GWP (Mt CO2_eq)-145 Mt 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 5: Total demand of wood for buildings (solid wood, wood frame, wood fibre 

insulation and OSB/MDF boards) for new buildings in the EU – upper limit               

(Source: Legep & BEAM² Modelling) 

The  use  of  wood  –  as  well  as  the  global  warming  savings  potential  –  could  be 
increased by applying wood products to building renovations. This would mainly affect 
wooden  insulation  such  as  wood  fibre  insulation  board  and  medium  density  fibre 
board.  However,  it  bears  significant  potential  since  energy  efficient  renovations  need 
to take place across Europe and wood could very well replace most of the conventional 
insulation  materials  like  mineral  wool  or  EPS/XPS.  Thus,  including  wood  as  a  key 
material in the EU “renovation wave” and other activities would be very beneficial.   

June 2020  I  12 

0102030405060708090100Million m³Total m3 of wood -upper limittotal solid wood m3 - upper limittotal wood frame m3 - upper limittotal million m3 of wood eq. for insulation - upper limittotal million m3 of OSB - upper limitMillion m³ 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Introduction 

Background 
Building operations are becoming more and more efficient during their use phase, and 
from 
the  share  of  energy  and  greenhouse  gas  (GHG)  emissions  resulting 
manufacturing  of  materials  and  construction  processes  are  becoming  more  dominant 
in  the  building  life  cycle.  As  the  legislation  (primarily  the  Energy  Performance  of 
Buildings  Directive  -  EPBD)  focuses  on  the  operation  phase  of  buildings  only,  this 
aspect  is  not  yet  covered  from  a  building’s  perspective.  For  this  reason,  the  overall 
GHG  footprint  of  buildings  must  be  assessed  and  systematically  reduced  to  align  the 
building sector with the long-term target of a net-zero emissions system in Europe by 
2050,  as  laid  down  in  the  European  Commission’s  A  Clean  Planet  for  All  Strategy 
[European  Commission  (EC),  2018]  and  supported  by  the  EU  Green  Deal  [European 
Commission (EC), 2019].  
Depending on the impacts and advantages of using wood instead of mineral materials, 
promoting  wood  in  the  building  sector  can  be  useful  to  reach  long-term  energy  and 
climate  targets.  In  this  case,  life  cycle  assessment  (LCA)  methods  would  need  to  be 
further  specified  to  quantify  the  embodied  energy  and  GHG  emissions  of  building 
materials  and  production  processes,  along  with  additional  research  on  how  to 
implement  the  life  cycle  perspective  into  regulatory  law  (e.g.  phasing  out  of  fossil 
energy  subsidies  and  introduction  of  environmentally  friendly  taxes  and  emission 
trading systems, see chapter 4).  

Goal of the Study 
This study intends to (i) give an overview of the embodied GHG emissions of different 
building  construction  concepts  (mineral  vs.  wooden  constructions)  and  (ii)  highlight 
the  GHG  reduction  potential  of  using  wood  instead  of  mineral  construction  materials. 
The  analysis  over  the  entire  life  cycle  covers  the  operation  and  the  manufacturing  of 
the  materials  and  the  construction  of  the  building  –  and  ideally  the  eventual  reuse, 
recycling, and disposal of the materials.   
This  approach  is  in  line  with  the  priorities  of  the  new  EU  Green  Deal  [European 
Commission  (EC),  2019]  where  sustainable  construction  methods  and  a  circular 
economy  are  key  policy  areas  towards  2050.  The  European  Commission’s  in-depth 
analysis  regarding  a  net-zero  emissions  society  by  2050  in  the  “Clean  Planet  for  All” 
package [European Commission, 2018;] shows that circular economy and sustainable 
building concepts are required.  
Since  the  availability  of  wood  as  material  is  a  necessary  precondition,  the  additional 
availability of solid wood from EU forests is also considered in the analysis. In addition 
to the technical impacts of wooden buildings, the EU policy framework is assessed with 
regard  to  options  for  improvement.  Recommendations  are  also  provided  for  adapting 
EU policies. 

Overview of Methodology 
This  chapter  summarises  the  methodology  for  the  analysis  within  the  project  (see 
Figure  6).  Since  the  GHG  emission  reduction  potential  of  wooden  buildings  and 
construction  elements  within  the  EU  building  sector  is  determined  by  a  bottom-up 
approach, the first step of the methodology is to conduct a life cycle analysis (LCA) of 
representative individual buildings in work package 1 (chapter 2). Different building 
construction types like concrete, brick, stone, and wood are modelled and compared in 
detail  with  an  LCA  software.  The  full  life  cycle  of  buildings  is  considered,  from 
construction via use phase until demolition/ dismantling.  

June 2020  I  13 

 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 6: Overview of Methodology 

Based on material mass balances, a series of environmental indicators are calculated, 
where the GWP in CO2-equivalent units is the most relevant for this study.  

To  determine  a  possible  uptake  of  wooden  construction  elements  used  for  new 
buildings and retrofits, a baseline development of using wood in the EU building sector 
is  defined  in  work  package  2  (chapter  3).  Since  more  timber  would  need  to  be 
supplied from the forest sector to increase the wood market shares for new buildings, 
the  additional  available  potential  of  wood  from  EU  forests  is  analysed.  Based  on  this 
analysis,  the  theoretical  ad  hoc  potential  of  wooden  buildings  is  derived.  Additional 
constraints  can  lead  to  a  realistic  pathway  and  bandwidth  for  the  uptake  of  wooden 
buildings  and  building  elements  in  the  EU  until  2050.  Examples  of  such  constraints 
include the following:  

▪  Current new building and renovation rates 

June 2020  I  14 

 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

▪  Real availability of m3 of wood from the forest sector (includes the ramping up of 

capacities over the supply chain) 

▪  Availability of craftsmen and professional planners  

▪  The effects of a changing policy environment towards climate change 

The  pathways  are  described  in  detail  regarding  the  volumes  of  wood  used, 
replacement  of  other  building  materials,  and  the  GHG  savings  effects  for  the  carbon 
content  captured  within  the  wood  itself  and  the  GHG  emissions  saved  by  replacing 
other materials.  

The  policy  framework  (with  regard  to  wooden  elements  and  buildings)  is  briefly 
addressed  in  work  package  3.  In  a  first  step,  current  incentives  and  barriers  are 
analysed  on  the  EU  level.  Based  on  this  setup,  improvement  options  are  discussed, 
and recommendations are formulated towards an enabling framework.  

June 2020  I  15 

 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

LIFE CYCLE ASSESSMENT OF INDIVIDUAL BUILDINGS 
This  study  analyses  the  climate  impact  of  wooden  buildings  and  building  elements 
over the whole life  cycle in terms of  GHG emission reductions.  The  methodology and 
general  framework  of  LCAs  are  explained  in  Chapter  1,  while  the  following  Chapters 
2.2  –  2.5  are  oriented  along  the  stages  I-IV  of  LCAs  according  to  [EN  ISO  14040]. 
Figure 7 also depicts this framework. Stage I defines the overarching goal of the LCA 
and  sets  the  scope  of  the  analysis.  The  underlying  reference  buildings  and 
constructions  variants  are  also  defined  in  stage  I.  Stage  II  represents  the  life  cycle 
inventory, which consists of the mass and material balancing for all variants. This step 
is the basis for the impact assessment of the LCA in stage III. Here, the main results 
are  calculated  regarding  the  embodied  energy  and  GHG  emissions  (GWP)  of  the 
variants. Finally, stage IV evaluates and interprets the results.  

Key Findings of LCA on individual Building Level 

▪  In general, a life cycle analysis consists of (i) a definition of objective and scope, (ii) life 

cycle inventory, (iii) impact assessment and (iv) evaluation/interpretation. 

▪  Building life cycles are categorised in (A) product/construction stage, (B) use stage, (C) 

disposal/end-of life stage and (D) recycling potential stage. 

▪  As life cycle inventories show, mineral buildings have significantly higher material and 

mass streams than wooden buildings (which impact the global warming potential of the 
construction). 

▪  The impact assessment shows, that the global warming potential over the life cycle for 

wooden buildings with minimal 2 kg CO2_eq/m2 compared to mineral buildings with up to 
500 kg CO2_eq/m2 is marginal.  

▪  Apart from the temporary CO2-saving effect (carbon storage) of wood the substitution 
effect of mineral materials accounts for the largest part of the overall global warming 
potential.  

▪  For an average wooden single-family house this means 0.3 tonnes CO2_eq emissions for 
the construction process and at the same time 42.8 tonnes of CO2_eq stored in the wood 
itself over the lifetime, while an average mineral single-family house accounts for 73.5 
tonnes of CO2_eq emissions for the construction process. This seems quite a lot compared 
to an average CO2-footprint of 7 tonnes for an average European citizen in 2018 
according to Eurostat greenhouse gas statistics. 

Methodology - Introduction to LCA  
Based on the general definitions of LCA from [EN ISO 14040, 2009], the full life cycle 
of  buildings  is  considered  in  multiple  phases  according  to  building-specific  definitions 
in  [EN  15804,  2014]  from  construction  via  use  phase  until  dismantling,  demolition, 
and  reuse.  The  individual  analysis  determines  the  GHG  savings  for  wooden  buildings 
compared  to  brick,  stone,  and  concrete  concepts.  The  substitution  effect  (producing 
wooden  building  elements  instead  of  alternatives)  and  the  CO2-storage  within  the 
material  wood  are  analysed.  This  chapter  focuses  on  LCA  of  individual  buildings.  A 
scaling up of the GHG-saving effect towards higher wooden buildings market share for 
new construction – also considering the available resources from the forestry sector – 
is elaborated on in chapter 3. 

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    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Five reference buildings for the LCA calculation provide guidance on how to determine 
what  sustainable  building  material  will  cut  GHG  emissions.  These  variants  consist  of 
frequently  used  wall  structures  with  different  core  elements.  Two  of  these  variants 
focus  on  timber  construction  (solid  wood  and  wooden  frame)  and  the  other  three  on 
mineral  construction  (vertically  perforated/honeycomb  bricks,  sand-lime  stones,  and 
reinforced concrete/cellular concrete). These variants serve as basis for the definition 
of energy balances, mass balances, and the calculation of the GWP saving potential.  

The  analysis  is  based  on  the  modelling  of  different  building  construction  types  for 
multiple reference building types with the LCA software LEGEP.4 This LCA tool is used 
to  evaluate  the  GWP  calculations  for  each  of  the  variants.  It  is  in  line  with  the 
definitions  of  [EN  ISO  14040,  2009]  and  [EN  15804,  2014].  The  main  result  of  this 
calculation  is  the  GWP  in  terms  of  CO2-equivalent  GHG  emissions.  Finally,  a  basic 
comparison to the LEVEL(S) framework is conducted. 

General Concept of LCA 
LCA  is  a  compilation  and  evaluation  of  the  inputs,  outputs,  and  the  potential 
environmental  impacts  of  a  product  system  throughout  its  life  cycle  [EN  ISO  14040, 
2009].  Therefore,  it  considers  all  product  phases  from  mining,  manufacturing, 
production,  usage,  end-of-life,  recycling,  and  disposal.  There  are  two  main  principles 
to be followed when conducting LCAs.  

▪  Cross-media consideration: All potentially relevant harmful effects on environmental 

media (soil, air, and water) must be taken into account. 

▪  Material flow consideration: All material flows associated with the system (raw 

material inputs and emissions from preliminary and disposal processes, from energy 
generation, transport, and other processes) must be taken into account. 

According to [EN ISO 14040, 2009], an LCA can assist in: 

▪  Identifying opportunities to improve the environmental performance of products at 

various points in their life cycle 

▪  Informing decision makers in industry, government or nongovernment organisations 

(e.g. for the purpose of strategic planning, priority setting, product or process 
design or redesign) 

▪  Selecting relevant indicators of environmental performance, including measurement 

techniques  

▪  Marketing (e.g. implementing an ecolabelling scheme, making an environmental 

claim, or producing an environmental product declaration) 

An  LCA  consists  of  the  following  four  stages  (see  Figure  7):  (i)  definition  of 
objective and scope, (ii) life cycle inventory, (iii) impact assessment, and (iv) 
evaluation/interpretation.  This  study  is  conducted  along  the  ISO  14040  standard. 
It defines the objective and scope of the analysis (GHG emissions and global warming 
as  a  main  indicator  over  the  entire  building  life  cycle),  defines  a  life  cycle  inventory 
(mass balances and material flows), conducts the impact assessment (combination of 
material flows and impact categories/indicators in LEGEP), and evaluates the results of 
the analysis. 

4 See www.legep.de for technical details.  

June 2020  I  17 

 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 7: Stages of an LCA [EN ISO 14040, 2009] 

Relevant Standards 
In  that  framework,  a  range  of  European  standards  are  relevant  for  LCAs.  ISO  14040 
and  14044  define  general  principles,  a  framework,  requirements,  and  guidelines  for 
LCAs (of all product categories in general), while EN 15804 and EN 15978 focus on the 
construction  sector  and  spefify  EPDs  (Environmental  Product  Declarations)  and 
calculation methods for constructions works:  

▪  ISO 14040: Life Cycle Assessment – Principles and Framework 

▪  ISO 14044: Life Cycle Assessment – Requirements and Guidelines 

▪  EN 15804: Sustainability of Construction Works – EPDs – Core Rules for the Product 

Category of Construction Products 

▪  EN 15978: Sustainability of Construction Works – Assessment of Environmental 

Performance of Buildings – Calculation Method 

ISO 14040: Life Cycle Assessment – Principles and Framework 
Since  there  is  growing  importance  of  environmental  protection  and  the  need  to 
understand  possible  impacts  of  products  on  the  environment,  the  interest  in 
understanding  and  addressing  these  impacts  has  risen.  The  LCA  has  been  developed 
as one of the methods to measure these impacts. International rules were created for 
carrying out LCAs in the ISO standards 14040:2006 and 14044:2006. These standards 
were then transferred into national standards.  

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    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

ISO 14040 gives details and definitions on key features, scope, general principles, and 
phases of an LCA, Life Cycle Inventory Analysis (LCIA), system boundaries, and other 
relevant aspects (reporting, critical review). 

ISO 14044: Life Cycle Assessment – Requirements and Guidelines 
Based  on  the  foundation  of  ISO  14040,  the  ISO  14044  standards  details  the 
methodological  framework,  reporting,  and  a  critical  review  of  all  aspects  regarding 
LCA. 

EN  15804:  Sustainability  of  Construction  Works  –  EPDs  –  Core  Rules  for  the 
Product Category of Construction Products 
The  EN  15804  standard  provides  basic  rules  for  LCA  of  all  construction  products  and 
services  witin  the  general  framework  of  ISO  14040.  It  builds  the  foundation  of  all 
EPDs.  Construction  products,  construction  works,  and  construction  processes  are 
verified  and  presented  consistently.  An  EPD  communicates  verifiable,  accurate,  non-
deceptive  environmental  information  for  products  and  their  application.  It  supports 
scientifically  based,  fair  decisions  and  creates  an  incentive  for  a  continuous 
improvement of environmental quality.5 
This  European  standard  provides  basic  product  category  rules  for  EPDs  for 
construction products and services. EPDs facilitate the selection and documentation of 
products  during  construction.  They  provide  the  basis  for  LCAs.  The  LCA-based 
information of an EPD typically includes the following, see Figure 8: 

▪  Only the product stage. Such an EPD includes the provision of raw material, 

transport, manufacture, and related processes. This EPD is called cradle to gate6, 
and becomes an EPD based on the information modules A1 to A3. 

▪  The product stage and other selected phases of the life cycle. This EPD is called 

cradle to gate with options and becomes an EPD based on the information modules 
A1 to A3, plus other selected optional modules, e.g. the disposal describing modules 
C1 to C4 (if the manufacturer is responsible for it). Information module D can be 
included in this EPD. 

▪  The life cycle of a product according to the system boundaries. In this case, the EPD 

includes the product stage, construction process, use stage and inspection incl. 
maintenance and replacement, disposal (end-of-life) including waste treatment for 
reuse, recovery and recycling. This EPD is referred to as cradle to grave and is an 
EPD for construction products based on a LCA, which takes into account all 
information modules A1-C4. Information module D can be included in this EPD. 

5 Source: [DIN EN 15804:12 + A1:2013] 
6 "exit gate" of the last company involved in the production process is meant. 

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    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 8: Lifecycle of a building according to EN 15804                                           

(Source: [EN 15804, 2014] by CEI-Bois)  

The disposal phase of a construction product begins with the replacing, removing, or 
dismantling materials from the building when they no longer has any further function. 
This  phase  can  also  begin  with  the  disposal  phase  of  the  building  itself.  The  total 
output from the dismantling is not considered as waste if [EN 15804, 2014] … 

▪  …the recovered material, product, or component is commonly used for specific 

purposes.7 

▪  …there is a market characterised by a positive economic value for the recovered 

material, product, or component, or a demand for it. 

▪  …the recovered material, product, or component fulfils the technical requirements 
for the specified purposes and complies with existing legislation and standards for 
products. 

▪  …the use of the recovered material, product, or component does not lead to overall 

adverse environmental or health impacts. 

The disposal phase includes dismantling, transport, waste treatment, and waste 

disposal. Pollutions (e.g. emissions) from waste disposal are considered to be part 
of the investigated product system according to the polluter-pays principle. 
However, if such a process is used to generate energy, such as electricity and heat 
from waste combustion or landfill gas, then the potential credits from this usable 
energy are assigned to Module D (Potential after LC, see Figure 9). The calculation 
is based on average substitution processes [EN 15804, 2014]. For wooden 
construction material the thermal combustion corresponds to the standard scenario. 
Positive emissions from the CO2-content of wood are considered, but at the same 
time some negative emissions from replaced fossil energy carriers for combustion. 
This means, that the CO2-emissions captured by wood as material are not released 
right after harvest, but delayed with the lifetime of the material. If the wood is 
burned or rotting, the CO2-emissons are released again. Therefore, it it important to 
extend the lifetime of wood as recycled material as long as possible in order to delay 

7  The  "specific  purpose"  is  not  limited  to  the  function  of  a  particular  product,  but  may  also  apply  to  a 
material  used  as  input  to  the  production  process  of  another  product  or  to  the  production  of  energy  EN 
15804, 2014. 

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    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

the emissions as long as possible. It would make sense to focus on reusing wood as 
much as possible and ensuring any loss through burning is replaced with new wood. 
This would maximise the potentials sink. Once saturation is reached, this level of 
wood product stock would have to be maintained on the long-term, to avoid 
becoming a source of emissions later. 

Figure 9: Decision chart for the end of the waste characteristic [EN 15804, 2014]  

The potential after LC (Modul D) aims to provide transparency on the environmental 
benefits  or  impacts  caused  by  recyclable  products,  recycled  materials,  or  usable 
energy sources leaving the product system. All declared credits and debits leaving the 
product system that are not considered co-products and that have reached the end of 
their waste characteristics must be assigned to module D. Avoided effects of assigned 
co-products must not be assigned to Module D [EN 15804, 2014].  

EN  15978:  Sustainability  of  Construction  Works  –  Assessment  of 
Environmental Performance of Buildings – Calculation Method 
The  EN  15978    provides  calculation  rules  for  the  assessment  of  the  environmental 
quality  (environmental  performance)  of  new  and  existing  buildings  based  on  the 
specific  framework  of  EN  15804  for  construction  work  and  the  general  framework  of 
LCA  within  ISO  14040.  Its  calculation  method  is  based  on  the  LCA  data,  as  well  as 
tools  for  reporting  and  communicating  the  outcome  of  this  assessment.  It  applies  to 
new and existing buildings and to refurbishments.8   

This standard contains 

▪  The description of the purpose of the assessment 

▪  The system boundaries applicable at the building level 

8 Source: DIN EN 15978 

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    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

▪  The procedure used for the inventory analysis 

▪  A list of indicators and methods for calculating these indicators 

▪  The requirements for the presentation of results in reporting and communication  

▪  The requirements for the data required for the calculation 

This assessment approach covers all phases of the building life cycle and is based on 
the data taken from the relevant EPDs, their information modules [EN 15804, 2014], 
and other information necessary and relevant for the performance of the assessment. 
The  assessment  includes  all  building-related  construction  products,  processes,  and 
services used throughout the life cycle of the respective building. 

EU Level(s) Framework 

Level(s) is a voluntary reporting framework to improve the sustainability of buildings. 
Using existing standards, Level(s) provides a common EU approach to the assessment 
of environmental performance in the built environment. The buildings sector is one of 
the most  resource consuming sectors in Europe, accounting for approximately half of 
all  extracted  materials,  half  of  total  energy  consumption,  one  third  of  water 
consumption  and  one  third  of  waste  generation.  That’s  why  the  buildings  sector  is  a 
key  target  in  the  European  Commission’s  policy  for  circular  economy;  a  regenerative 
economic  system  in  which  resource  and  energy  consumption  are  minimised.  Level(s) 
is a sustainability framework of the circular economy, and offers a tiered approach to 
life cycle assessment. Source of this overview is [EC, 2017]. 

The Level(s) common framework of core indicators aims at: 

▪  Raising awareness of, and demand for, better buildings - among the general public, 

developers and public procurement offices;  

▪  Improving knowledge of resource efficiency in the built environment to support 

better decision making on the part of designers, architects, developers, construction 
companies, construction product manufacturers, investors, and building owners. 

Within  the  framework,  each  indicator  is  designed  to  link  the  individual  building’s 
impact with the priorities for sustainability at the European level. These priorities are:  

▪  Greenhouse gas emissions throughout the building’s life cycle with a focus on 

production/construction phase as well as on removal/disposal/recycling phase. 

▪  Resource efficient and circular material life cycles  

▪  Efficient use of water resources  

▪  Healthy and comfortable spaces  

▪  Adaptation and resilience to climate change  

▪  Life cycle cost and value 

Each  indicator  within  Level(s)  can  be  used  for  different  types  of  performance 
assessment,  from  a  basic  level  through  to  a  full  Life  Cycle  Assessment  (LCA).  The 
entry point to Level(s) is through the common performance metrics: the simplest and 
most accessible use of each indicator. Level(s) sets out common units of measurement 
and  basic  calculation  methodologies,  which  can  be  used  by  building  professionals, 
building assessment schemes, investor reporting tools and public sector initiatives. To 
compare  the  environmental  performance  of  buildings,  at  a  portfolio  or  national  level, 
Level(s)  offers  the  option  of  comparative  performance  assessment.  This  option  is 
suited  to  building  professionals  and  owner  of  property  portfolios.  For  building 

June 2020  I  22 

 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

professionals  working  at  a  more  detailed  level  to  improve  performance  and  optimise 
design and as-built performance, the design performance optimisation represents the 
most  sophisticated  use  of  each  indicator.  To  minimise  the  gap  between  design,  as-
built and occupied performance, users can report on the indicators at different project 
stages:  design  stage  (based  on  calculations),  completion  stage  (based  on  as-built 
drawings),  post-completion  (based  on  commissioning  and  testing),  and  post-
occupancy (based on measured performance). 

A  report  of  JRC  on  Level(s)  explains  the  structure  and  objectives  [JRC,  2017].  The 
Level(s)  framework  consists  of  six  macro-objectives,  which  set  goals  for  the 
contribution  of  buildings  across  the  EU  to  environmental,  health  and  comfort,  and 
cost, value and risk objectives. Based on these goals, building specific indicators have 
been developed. In this way, users can be sure that by using the Level(s) framework, 
or  schemes  or  tools  that  are  aligned  with  the  framework,  they  are  contributing  to 
meeting these goals. An overview of the indicators, scenarios and LCA tools that form 
part of the Level(s) framework is presented in Figure 10. 

Figure 10: Overview of the Level(s) framework. Source: [JRC, 2017] 

Before  Level(s)  can  be  launched  on  the  market  and  start  constituting  a  basis  for 
different  policy  and  business  initiatives,  it  has  to  be  thoroughly  tested  by  building 
professionals  across  Europe.  For  this  purpose,  the  European  Commission  opened  a 
two-year  testing  phase  for  Level(s)  in  spring  2018.  During  the  testing  phase, 
stakeholders  across  the  construction  and  real  estate  value  chain,  from  investors,  to 
developers,  designers  and  manufacturers,  are  supported  in  testing  the  Level(s) 
indicators  on  their  respective  building  projects.  The  feedback  from  the  testing  phase 
will  inform  the  final  version  of  the  Level(s)  framework  –  to  be  launched  around 
summer  2020.  Level(s)  is  being  tested  in  more  than  130  building  projects  in  21 
countries. [JRC, 2017] 

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    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Stage I: Goal and Scope of LCA 
In the first step, the goal and scope of the LCA is defined. As stated, the overarching 
goal  is  to  calculate  the  overall  impacts  of  the  category  GHG  emissions  for  different 
building types  over  the  entire  life  cycle.  A  comparison  between  different  construction 
variants gives then insights on the environmental performance of these variants. 
The  scope  of  the  analysis  is  set  to  three  reference  building  types  and  five 
constructions  variants.  They  are  analysed  within  the  general  scope  of  EN  ISO  14040 
and  the  specific  life  cycle  phases  for  buildings  according  to  EN  15804.  The  following 
chapters summarise the reference buildings and constructions variants as well as the 
energy performance. 

Reference Buildings and Construction Variants 
Since  the  aim  of  the  analysis  is  to  determine  the  overall  GHG  reduction  potential  for 
wooden  buildings  and  construction  elements  in  Europe  with  a  bottom-up  approach, 
individual reference building cases need to be defined. In this project’s framework, we 
use the following three reference building geometries: 

▪  Single-family house (SFH) with 147 m2 floor area 

▪  Multifamily house (MFH) with 1,290 m2 floor area  

▪  Office building (OFB) with 6,998 m2 gross floor area 

The SFH and MFH are based on reference buildings of [Dietmar Walberg et al., 2015], 
while  the  OFB  is  based  on  a  building  on  typical  reference  buildings  from  [Klauß  and 
Kirchhof, 2010]. These  reference buildings do  not represent  example  buildings based 
on  individual  evaluations,  but  rather  reflect  the  current  construction  practise  across 
Germany and Europe. Detailed definitions of the reference buildings can be in Annex I. 

As  part  of  this  study,  the  reference  buildings  are  organised  in  the  following  five 
construction variants to analyse and compare their GHG balances:  

▪  Vertically perforated/honeycomb bricks 

▪  Sand-lime stones  

▪  Reinforced concrete/cellular concrete as mineral materials  

▪  Wooden frame constructions  

▪  Solid wooden elements 

Different thicknesses of the load-bearing layers have been defined in consultation with 
experts on buildings structural analysis to meet the statics requirements. The detailed 
definitions  of  foundations,  basement,  walls,  ceilings,  and  roofs  for  the  different 
construction variants can be found in Annex I. Since reinforced concrete is unusual for 
SFHs, this variant is not considered, whereas bricks and wood frame constructions are 
not considered as typical variants for office buildings.  

The primary building materials for mineral constructions are sand-lime stones, bricks, 
and  reinforced/cellular  concrete.  Regarding  wooden  building  variants,  the  following 
wooden or wood-based construction materials are used: 

▪  Sawn-wood: Massive wooden beams and planks, technically dried with dimensional 

stable properties.    

June 2020  I  24 

 
 
 
 
 
 
 
  
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

▪  Glulam: Glued laminated timber in form of beams and sometimes also boards, 

which are composed of single planks. 

▪  CLT: Cross-laminated timber elements consists of different oriented layers of 

wooden planks and/or beams, which are glued or dowelled together to a massive 
panels. 

▪  OSB: Oriented strand boards consist of compressed layers of wood strands (flakes) 

in specific orientations glued together with adhesives.  

▪  MDF: Medium density fibre boards are used similar to OSB for construction 

purposes. 

▪  WFIB: Wood fibre insulation boards consist mainly of wood fibres and are used for 

insulation purposes. 

Energy Balances  

This chapter details the building energy demand for heating (energy balances) for the 
combinations  of  reference  building  and  construction  variant.  The  variants  of  a 
reference building are defined in a such way that the final and primary energy demand 
for  heating  is  the  same.  This  allows  for  a  direct  comparison  of  the  construction 
variants  and  differences  in  GHG  emissions  for  manufacturing  and  construction  of  the 
building.  
The final and primary energy demand for the SFH construction variants are shown in 
Table 1 with the heat transmission coefficient (u-value) of walls, windows, and roofs. 
They  are  in  line  with  requirements  for  new  buildings  in  nZEB  standard.  The 
corresponding structures and thicknesses of the components are shown in Annex I.  

Table 1: Annual primary energy demand and u-values of all SFH variants 

Energy  balances  for  the  MFH  and  the  office  building  are  also  be  found  in  Annex  I. 
While the final and primary energy per m2 are comparable between the SFH and MFH, 
the  office  buildings  values  are  significantly  lower  due  to  a  more  compact  A/V  ratio. 
Since  the  variants  per  building  do  not  differ  with  regard  to  final  and  primary  energy 
demand  for  the  operation  phase,  the  focus  lies  on  a  comparison  between  the 
embodied  energy  and  GHG  emissions  for  manufacturing  and  construction  and  on  a 
comparison to the use phase. 

Stage II: Lifecycle Inventory - Mass and Material Balances 
The  LCIA  involves  data  collection  and  the  calculation  procedures  to  quantify  relevant 
inputs and outputs of the system within the boundary conditions/scope of step I. For 
this  study,  the  data  collection  done  within  the  LEGEP  software  and  based  on  the 
databases  “Ecoinvent”  and  “Ökobau.dat”.  They  provide  the  necessary  environmental 
impact  indicators  on  European  level  for  all  relevant  materials  within  the  scope  of  the 
analysis  (e.g.  the  GWP  of  1  m³  of  concrete).  Furthermore,  the  mass  and  material 
balances  per  reference  building  type  and  construction  variant  are  calculated  in  this 
step. They are the key input to the impact assessment in stage III. 

June 2020  I  25 

Energyu-value wallu-value roofu-value winfinal energyprimary energyW/(m²K)W/(m²K)W/(m²K)kWh/(m²a)kWh/(m²a)Solid Wood (SW)0,170,170,6715,928,7Wood Frame (WF)0,170,170,6715,928,7Brick (BR)0,170,170,6716,028,7Sand-Limestone (SL)0,180,170,6716,128,9Cellular Concrete (CC)0,180,170,6716,128,9 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

The  mass  balance  of  the  variants  strongly  depends  on  the  material  used  for  the 
construction.  Since  wood  has  a  lower  density  than  mineral  construction  material,  the 
mass  of  the  two  timber  variants  is  lower  than  the  mass  of  the  two  mineral  variants. 
Table 2 and the following tables and graphs provide example for SFHs.  

Table 2: Comparison of the mass of the SFH variants 

Table 3 details the individual materials and their mass and volume per variant. Since 
these variants are all defined with a concrete basement, most of the mass is assigned 
here. The solid wood variant shows the highest amount of wood, while the wood frame 
variant  has  demand  for  OSB  panels.  For  brick  and  sand-limestone,  the  respective 
category gives the amount of material involved. 

Table 3: Masses and Volumes for main Construction Materials for the SFH variants 

Since a basement is included in all variants, the overall mass is mainly determined by 
the amount of reinforced concrete for the basement. However, the mass-related share 
of  renewable  raw  material  (wood  in  this  case)  for  the  solid  wood  and  wooden  frame 
variants  are  with  22%-14%  significantly  higher  than  for  the  mineral  materials  brick 
and sand-limestone (see Figure 11). 

Figure 11: Mass-Ratio of renewable and non-renewable raw material of each variant                                                                               

related to the mass of the SFH with basement 

If  the  basement  is  not  considered,  the  material  percentages  shift  significantly,  as 
noted in Figure 12. Here the mass of wood accounts for 63% of the total mass for the 
solid  wood  variant  and  for  40%  at  the  wood  frame  variant,  whereas  almost  no 
changes occur for the mineral construction variants.  

June 2020  I  26 

MaterialMass totalMass basementMass  above basementtttSolid Wood (SW)19712770Wood Frame (WF)19412767Brick (BR)335127208Sand-Limestone (SL)349127222MaterialSolid Wood (SW)Wood Frame (WF)Brick (BR)Sand-Limestone (SL)tm3tm3tm3tm3tm3tm3408813659--57161163313659117712661610591958410212436581591968585611310181WoodConcreteBricks, StonesInsulationSteelOSBSolid WoodWooden FrameBrickSand-Limestone 
 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 12: Mass-Ratio of renewable and non-renewable raw material of each variant                                                                               

related to the mass of the SFH without basement 

Additional  details  and  all  data  regarding  the  mass  and  material  balances  on  the  MFH 
and office building can be found in Annex I. 

Stage III: Impact Assessment 
Based  on  the  life  cycle  inventory,  the  environmental  impact  assessment  is  the  core 
element  of  any  LCA.  The  following  sub-chapters  give  an  overview  on  the  impact 
assessment  results  for  the  reference  building  variants.  In  general,  the  IA  approach 
consists  of  a  variety  of  environmental  indicators  and  impact  categories,  but  this 
analysis focuses on the GWP in CO2_eq GHG emissions as a main indicator. 
LCAs  for  buildings  are  generally  structured  in  four  phases  according  to  EN  15804. 
While  all  process  and  energy-related  GHG  emissions  during  the  production  of 
components  and  construction  activities  onsite  are  covered  be  the  phases  A1  through 
A3  (including  the  credits  for  the  CO2  stored  in  wood),  retrofits  during  the  operation 
phase  of  the  building  are  covered  in  phases  B2  and  B4,  see  Figure  4.  In  in  disposal 
phase (C3-C4) the  GHG emissions involved for  the deconstruction of the building are 
assigned and benefits if the material can be recycled (e.g. concrete can be recycled to 
road  base  construction  material)  or  used  in  processes  (e.g.  wood  as  fuel  for  thermal 
powerplants).  
Overall, negative emissions can occur (i) in case of wood as building material for the 
temporary CO2-storage effect (where the CO2 is stored in the construction phase and 
released  again  during  the  disposal  phase)  and  (ii)  for  end-of-life  credits  (which  can 
cover  a  further  usage  as  material  -  alternatively  to  the  default  usage  covered  in  the 
disposal phase - and avoids new material resources). 

Single-Family House 

The GWP in terms of corresponding CO2_eq emissions related to the different phases for 
SFH between the construction variants are compared in Table 4.  

Table 4: GWP for the four SFH variants 

June 2020  I  27 

Solid WoodWooden FrameBrickSand-LimestoneGWP (EU Data)Manufacturing A1-A3Retrofit B2+B4Dsiposal    C3-C4End of LC      DGWP of SWt CO2eqt CO2eqt CO2eqt CO2eqSolid Wood (SW)-33,27,5084,80-46,20Wood Frame (WF)6,27,5036,80-23,80Brick (BR)72,57,5017,70-16,70Sand-Limestone (SL)67,97,9018,90-16,40Delta btw. SW and BR105,70,00-67,1029,50 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Solid wood and wood frame emit a relatively small amount of GHG emissions over the 
whole life cycle in the range of 75 – 150 kg CO2_eq/m2. This is compared to the mineral 
variants,  bricks  and  sand-limestone,  which  emit  around  450  kg  CO2_eq/m2.  The  main 
reason  for  the  difference  is  the  realtively  small  amout  of  energy  demand  for 
manufacturing,  transportantion,  and  constriction  of  wooden  building  elements  and 
non-existent process emissions (like for cement production) in comparison to mineral 
construction  materials  and  variants.  The  CO2-storage  effect  of  wood  is  only  partly 
considered in the overall balance over the life cycle since the CO2 absorbed in phase A 
(manufacturing) is by default released again in phase C (disposal) and only shares of 
the wood are assumed to go into phase D (where a material reuse is assumed as end-
of-life  and  the  corresponding  CO2  emissions  are  not  released  in  the  atmosphere 
again).  
However,  this  changes  if  only  the  GWP  for  manufacturing  is  analysed.  Since  the  CO 2 
storage  of  wood  is  considered  with  917  kg  of  CO2  per  m2  of  wood  [Wegener  et  al., 
2010],  but  not  the  release  of  stored  carbon  into  the  athmosphere,  the  solid  wooden 
variant (with its high volume of wood) concludes with -193 kg CO2_eq/m2 and the wood 
frame variant with 36 kg CO2_eq/m2. In comparison, the mineral variants rank around 
400 kg CO2_eq/m2 of of GHG emissions for manufacturing only. 
Generally, the differences in CO2-emissions of the four variants mainly depend on the 
ratio  of  renewable  to  non-renewable  raw  material.  Even  wooden  buildings  do  not 
consist entirely of wood. For example, windows are always made of glass, floor slabs 
are  always  made  of  reinforced  concrete,  staircases  are  often  made  of  reinforced 
concrete  for  fire  protection  reasons,  and  the  building  technology  mainly  consists  of 
metal and plastics. 

Multi-Family House 

Table 5 shows the results for the impact assessment on MFH in terms of corresponding 
CO2_eq emissions related to the different phases.  

Table 5: GWP of the five MFH variants 

June 2020  I  28 

GWP (EU Data)GWP of SWSolid Wood (SW)Wood Frame (WF)Brick (BR)Sand-Limestone (SL)Delta btw. SW and BRtotaltotalonly Manu-facturingonly Manu-facturingt CO2eqkg CO2eq/m2t CO2eqkg CO2eq/m212,975,69-33,2-193,9026,7156,116,236,2381,0473,7472,5424,0378,3458,1467,9397,3268,1398,05105,7617,93GWP (EU Data)Manufacturing A1-A3Retrofit B2+B4Dsiposal    C3-C4End of LC      DGWP of SWt CO2eqt CO2eqt CO2eqt CO2eqSolid Wood (SW)-218,734,40422,00-235,50Wood Frame (WF)-6,532,90118,00-102,70Brick (BR)320,632,6053,10-61,90Sand-Limestone (SL)318,949,6070,30-71,40Reinforced Concrete (RC)337,766,3078,40-92,20GWP (EU Data)GWP of SWSolid Wood (SW)Wood Frame (WF)Brick (BR)Sand-Limestone (SL)Reinforced Concrete (RC)totaltotalonly Manu-facturingonly Manu-facturingt CO2eqkg CO2eq/m2t CO2eqkg CO2eq/m22,22,85-218,7-286,2941,754,62-6,5-8,47344,4450,77320,6419,62367,4480,85318,9417,37390,2510,74337,7442,03 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Comparabe  to  the  SFH  results,  the  construction  variants  solid  wood  and  wood  frame 
for MFH emit a relatively small amount of GHG emissions over the whole life cycle, in 
the  range  of  0–55  kg  CO2_eq/m2  compared  to  the  mineral  variants  with  bricks  and 
sand-limestone  with  around  450–510  kg  CO2_eq/m2.  The  spread  between  the  wooden 
variants  in  relation  to  the  mineral  variants  is  even  larger  than  for  SFH,  since  for 
structural  reasons  (statics),  more  material  is  needed  in  the  lower  levels  for  the  MFH 
with its five storeys above basement.  

The big differences between wooden and mineral buildings mirrors SFH. The realtively 
small amout of energy demand for manufacturing, transportantion, and constriction of 
wooden  building  elements  and  non-existent  process  emissions  (like  for  cement 
production)  in  comparison  to  mineral  construction  materials  and  variants  is  relevant 
here. 

When  only  focusing  on  the  manufacturing  GHG  emissions,  the  solid  wooden  variant 
shows more extreme values compared to the wood frame and the mineral variants per 
m². For solid wood, the manufacturing phase concludes with a negative GHG value of 
-286 kg CO2_eq/m2, while the wood frame variant is almost carbon neutral with  -8 kg 
CO2_eq/m2. The mineral variants show slightly higher GHG emissions with 417–442 kg 
CO2_eq/m2 compared to the SFH. 

Office Building 

Table  6  shows  the  impact  assessment  results  for  the  office  building  variants  in  the 
same  way  as  for  SFH  and  MFH  in  terms  of  corresponding  CO2_eq  emissions  related  to 
the different phases.  

Table 6: GWP of the three Office variants 

Since  the  wood  frame  and  brick  construction  variant  have  not  been  assesst  for  the 
office  building,  the  overview  gives  only  results  for  solid  wood,  sand-limestone,  and 
reinforced concrete constructions.  
In contrast to the the results of SFH and MFH, the office buildings GHG emissions per 
m²  and  construction  variant  are  not  as  differentiated.  This  is  primarily  due  to  the 
different  design  and  load-bearing  concept  for  the  office  building.  Since  the  loads  are 
centrally bundled in pillars, the outside and inside walls do not have to be desined as 
strong  as  for  the  other  concepts,  especially  the  five-storey  multifamily  building.  This 
leads to lower materials demands on average and to a smaller GHG footprint  per m² 
of floor area.  
The  GWP  for  the  solid  wood  variant  is  near  0  kg  CO2_eq/m2  while  the  sand-limestone 
and  reinforced  concrete  variants  rangk  around  315–323  kg  CO2_eq/m2  for  the  whole 
LCA.  When  focusing  only  on  the  manufacturing  GHG  emissions,  the  solid  wooden 
variant  shows  negative  values  around  -260  kg  CO2_eq/m2,  while  the  mineral  variants 

June 2020  I  29 

GWP (EU Data)Manufacturing A1-A3Retrofit B2+B4Dsiposal    C3-C4End of LC      DGWP of SWt CO2eqt CO2eqt CO2eqt CO2eqSolid Wood (SW)-1.631,8256,643.148,31-1.756,94Sand-Limestone (SL)1.710,9266,12377,18-383,09Reinforced Concrete (RC)1.745,9342,76405,32-476,66GWP (EU Data)GWP of SWSolid Wood (SW)Sand-Limestone (SL)Reinforced Concrete (RC)totaltotalonly Manu-facturingonly Manu-facturingt CO2eqkg CO2eq/m2t CO2eqkg CO2eq/m216,22,60-1.631,8-261,461.971,1315,831.710,9274,132.017,3323,241.745,9279,75 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

show significant positive emissions aground 275 kg CO2_eq/m2 for the same reasons as 
elaborated above.  

Stage IV: Evaluation and Interpretation 
The  impact  assessment  of  individual  buildings  is  conducted  for  the  scope  of  SFHs, 
MFHs,  and  office  buildings  with  the  construction  variants  solid  wood,  wood  framed, 
bricks,  sand-limestones,  and  reinforced/cellular  concrete.  Overall  the  goal  is  to 
compare the impact category GWP in terms of GHG emissions over the life cycle. The 
building shell of each variant has been defined so that the energy demand for different 
construction variants per building type is the same. The differences in embodied GHG 
emissions are directly comparable. 
The  main  differences  between  the  construction  variants  are  compared  in  Figure  13. 
The columns per variant show the GHG emissions for manufacturing and construction 
(phase A), retrofit (phase B), disposal (phase C), end-of-life (phase D), and the total. 
The manufacturing GHG emissions for wooden buildings (and especially the solid wood 
concept  with  a  high  amount  of  wood)  are  negative  compared  to  significant  positive 
GHG emissions for phase A for the mineral variants. This is because the CO2 stored in 
wood  is  included  here  as  credit.  It  is  fully  released  in  the  disposal  phase  (phase  C). 
Here, the columns show significantly higher values for the wooden building concepts. 
Finally,  the  end-of-life  GHG  emissions  (phase  D)  are  accounted  for  and  they  are 
negative for all variants, but are significantly larger for the solid wood case. This step 
accounts  for  the  use  of  materials,  and  there  is  more  potential  for  solid  wooden 
elements  in  comparison  to  wood  frame  buildings  (with  less  amount  of  wood)  or 
mineral  buildings  (where  typically  only  the  recycling  of  concrete  and  stones  for  road 
base material is an option).   

Figure 13: Global Warming Potential (GWP) over the Life Cycle of MFH Construction 
Variants without Use Phase (Source: Legep Modelling) 

In relation to the EU Level(s) framework, the LCA of individual buildings in this chapter 
corresponds  to  the  first  macro-objective  “GHG  emission  along  a  buildings  life  cycle”. 
The overarching indicator is the GWP over the life cycle of the building, together with 
the  use  stage  energy  consumption.  In  Level(s),  further  objectives  like  resource 

June 2020  I  30 

241344367390Solid Wood MFHWood Frame MFHBrick MFHSand-Limestone MFHReinforcedConcreteMFHGWP (t CO2_eq)Building lifecycle information according to EN 15804Manufacturing/construction (phase A), Retrofit (phase B2-5), End of life (phase C), Recycling Potential (phase D)Increase of GWPDecrease of GWP 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

efficient  and  circular  material  life  cycles  and  efficient  use  of  water  resources  play  a 
role  in  the  overall  LCA  context.  They  are  also  part  of  the  full  LCA  within  the  Legep 
software that is used for the analysis, but they are not focus areas of the study. 

Impact of Wooden Buildings on the EU Building Sector 
This  chapter  is  based  on  the  individual  building  LCA  from  chapter  2.  It  shows  the 
impact of higher wood market shares for new buildings across the EU by aggregating 
the  individual  LCA  results  with  a  bottom-up  approach.  Section  1  includes  a  baseline 
pathway  developed  based  on  trends  regarding  wood  as  a  construction  material.  An 
upper limit pathway is developed in  section 2 to show the  full impact of higher wood 
market  shares  for  new  buildings.  This  step  involves  an  analysis  of  EU  forests  (in 
section  3)  to  determine  the  additional  amount  of  wood  available  for  the  construction 
sector  as  well  as  additional  constraints  for  the  uptake  of  the  wood  market  shares 
across Europe. Overall, the aim of this chapter is to show the potential GHG emission 
savings of wooden buildings over the full life cycle of buildings. 

Key Findings on EU Building Sector Level 

▪  Currently, approx. 5.5% of the new buildings in Europe are constructed with wood as 

main material (with significant differences between MS) 

▪  Main types of wooden products used for new buildings are sawn-wood, glulam, CFL,          

OSB and WIFB. 

▪  In the baseline pathways, the wood quota keeps growing with 3% p.a., which leads to a 

quota of 13% by 2050 for residential and non-residential buildings 

▪  This leads 2.4 Mt GHG-emissions in 2050 over the LC for a 13% wood quota, while the 
same buildings in mineral construction would have GHG-emissions of 24 Mt in 2050 
(substitution effect). 

▪  The potential of wood from EU forests is not deployed yet (more m³ are re-growing each 
year than is extracted). Depending on the study and approach 60 Mm² - 235 Mm³ of 
additional wood is available within the EU.  

▪  Taking further constraints into account, the maximum realistic uptake of the wood quota 

is seen at 75% of the new building rate. 

▪  The GHG for wooden buildings at that level would be 11.6 Mt GHG-emissions, while the 
same share of buildings in mineral construction would add up to 73 Mt GHG emissions 
(substitution effect).  

▪  Together with the CO2-storage in wood, 145 Mt GHG emissions can be saved in 

comparison to typical mineral buildings.  

▪  For the upper limit pathway 90 Mm³ of additional wood resources would be needed – 

which is a realistic scale of additional wood from EU forests. 

Methodology for EU Building Sector Scenarios 
This  chapter  determines  the  building  sector  activities  and  corresponding  GHG 
emissions  in  the  building  sector.  Based  on  new  building  rates,  wood  market  shares, 
and definition of replaced building construction types, the GHG emissions savings are 
calculated  for  wooden  buildings in the baseline. This  step of  scaling  up results to the 
EU  building  sector  is  done  with  the  Navigant  BEAM²  Model,  which  is  an  integrated 

June 2020  I  31 

 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

assessment model for the European buildings sector (see details in Annex II) and has 
been  used  from  many  impact  assessments  of  the  EU  building  sector  (e.g.  in  the 
framework of the EPBD or the Smart Readiness indicator for buildings).  
The overall aim of the methodology is to scale up the results from the individual LCA 
in  chapter  2  to  the  European  building  sector  and  to  differentiate  between  the 
substitution effect of wood (replacing minerals materials) in terms of GHG savings 
and the CO2 storage effect of wood (since each m³ of wood stores 917 kg of CO2 as 
long as it is in use and not burned  or  rotting). This is done for all new buildings in a 
baseline  pathway  with  BAU  trend-assumptions  on  the  wood  market  shares  and  an 
upper limit pathway with high shares of wood in new buildings. 

Determination of the Baseline  
To determine the baseline for new buildings and the effect of wood market shares, the 
current picture  and recent trends need to be  analysed. Therefore, new building rates 
since  2012  are  analysed  based  on  a  recent  Navigant  study  for  the  EC  on  renovation 
and  new  building  rates.  Furthermore,  the  replacement  mix  of  mineral  buildings  is 
determined, which can be partly replaced by wooden buildings in the future pathways. 
Finally, the baseline GHG emission savings are shown with the necessary (additional) 
wood demand for this pathway. 

New Building Rates and Wood Market Shares 

Based on the recent Navigant study [Esser et al., 2019], an average new building rate 
of 0.7% for residential and 1.1% for non-residential buildings has been observed (see 
details  in  Annex  II).  These  figures  are  used  as  new  building  rates  in  this  study  (see 
Figure 14). 

Figure 14: New buildings in the EU (residential and non-residential) and baseline for 
wood market share (Source: BEAM²) 

The wood building market share (defined as share of all new buildings) in the  EU can 
be  approximated  with  5.5%  [Jakob  Hildebrandt  et  al.,  2017]  of  all  new  buildings  in 
2020.  The  average  growth  rate  of  this  wood  market  shares  of  3%  p.a.  [Jakob 
Hildebrandt et al., 2017] since 2000 leads to the definition of the baseline pathway, as 
shown  in  Figure  14.  A  total  wood  market  share  of  13%  for  residential  and  non-
residential  buildings  can  be  achieved  by  2050.  The  current  share  of  wood  frame 

June 2020  I  32 

 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

buildings within the wood market share is approximately 75% across the EU, while the 
remainder  (25%)  can  be  assumed  with  solid  wood  buildings  as  the  main  type  of 
construction. In the baseline pathways this share stays constant until 2050.  

Replaced Building Construction Types 

To determine the substitution effect of wooden buildings properly, the mix of replaced 
construction types must be determined. Since there is no European statistic about the 
primary  construction  materials  of  new  buildings  (on  average),  the  German  situation 
has  been  used  to  define  the  average  replaced  building  types  for  wooden  buildings, 
based  on  2018  statistical  values  for  new  building  permits  [DESTATIS,  2019].  This 
leads  to  an  average  use  of  40%  brick,  25%  sand-limestones,  and  35%  reinforced 
concrete/cellular  concrete  for  the  residential  sector.  While  the  proportion  for  sand-
limestone  is  the  same  for  non-residential  buildings,  a  large  share  shifts  to  reinforced 
concrete (60% in total) and only 15% remain for bricks, as shown in Figure 15.  

Figure 15: Replaced construction mix by new wooden buildings                                 

(Own calculations based on Destatis) 

Baseline GHG Emissions 

The  GHG  emissions  from  new  buildings  are  calculated  based  on  the  new  building 
activities for residential and non-residential buildings, the wood market share and the 
replaced  building  construction  types.  Figure  16  shows  the  GWP  over  time  for  new 
wooden buildings, with a wood market share of 5.5% in 2020 and increasing towards 
13% by 2050, which grows towards 2.4 Mt of CO2_eq emissions. 
If  these  buildings  were  built  with  the  average  mineral  construction  mix  from  above 
(replaced building constructions), a significantly higher share of GHG emissions would 
have been emitted, see Figure 17.  

Figure 16: GHG emissions (GWP) for new wooden buildings – baseline (Source: Legep 
& BEAM² Modelling) 

June 2020  I  33 

Assumption RESIDENTIAL EUAssumption Office NON-RESIDENTIAL EUReplaced construction mix2018Replaced construction mix2018Brick (BR)40%Brick (BR)15%Sand-Limestone (SL)25%Sand-Limestone (SL)25%Reinf. Concr. (RC) + (CC)35%Reinf. Concr. (RC) 60% 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 17: GHG emissions (GWP) for new mineral buildings (as alternative to wooden 
buildings) – baseline (Source: Legep & BEAM² Modelling) 

The  difference  between  these  GHG  emissions  is  the  substitution  effect  of  wooden 
buildings. It is shown in Figure 18 with the CO2-storage effect of wood (carbon content 
of wood). In the baseline, these effects add up to a total saving of about 24 Mt CO2-eq 
GHG emissions by 2050. 

Figure 18: GHG emissions (GWP) SAVINGS for CO2-storage in wood and substitution 
effect due to new wooden buildings – baseline (Source: Legep & BEAM² Modelling) 

To put this number into context, the  overall  GHG  emissions  of the European Building 
sector for the use phase of the buildings (EPBD scope) are shown in Figure 19. Target 
scenarios and shallow renovation scenarios are shown based on 2015 numbers. While 
the  two  target  scenarios  reach  approximately  90%  reduction  of  GHG  emissions,  the 
shallow  renovation  scenarios  levels  off  at  approximately  500  Mt  GHG  emissions. 
However, this figure shows that the saving potential about 24 Mt GHG emissions from 

June 2020  I  34 

 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

the  wooden  buildings  in  the  baseline  scenario  have  a  certain  effect,  but  are  not 
significant compared with the current emissions from usage of the buildings.  

Figure 19: Total CO2-Emission of EU27 building sector, Navigant 2015 

Baseline Wood Demand 

Taking  the  baseline  development  into  account,  the  overall  wood  demand  for  solid 
wood  and  wood  frame  buildings  (which  would  be  glulam  and  CLT  products)  and  for 
OSB/MDF and WFIB (wood fibre insulation boards) grows towards 14.8 Mm³ by 2050. 
Since the EU forest can supply at least an additional 60 Mm³, the baseline increase of 
3% wooden buildings per year can easily be covered.  
However,  a  higher  demand  for  wood  and  wood  products  is  given  in  the  upper  limit 
pathways, as noted in the next chapter.   

June 2020  I  35 

 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 20: Total demand of wood for buildings (solid wood, wood frame, wood fibre 
insulation and OSB/MDF boards) for new buildings in the EU – baseline (Source: Legep 
& BEAM² Modelling) 

Quantification of the Potential of EU's Forests  
This chapter aims to answer how much timber can be extracted from the EU’s forests 
up  to  2050  for  the  purpose  of  building  construction,  and  how  much  of  a  carbon  sink 
this represents. Carbon sequestration in wooden products with a long lifetime, such as 
wooden building frames, delays the release of carbon into the atmosphere and allows 
the regrowth of new forests that can then again absorb CO2. The dynamics of carbon 
sequestration in forests and products are explained and how the effects are measured. 
Subsequently,  we  discuss  the  structure  and  development  of  EU  forests  to  2030  and 
2050 under different scenarios. Finally, we discuss the conversion and end-use sector, 
focusing  on how much  of the wood  could be used  for the production  of  end-products 
like sawn-wood, CLT, glulam, OSB, WFIBs, or medium density fibre board (MDF). This 
chapter  summarises  the  findings,  while  the  detailed  analysis  and  figures  on  the  EU 
forest sector potential can be found in Annex II. 

Carbon Sequestration in Forests and Wood Products 
Before discussing the potential of the EU’s forests to supply wood for the construction 
sector,  a  common  understanding  of  the  dynamics  of  carbon  sequestration  in  forests 
and products is necessary. Forests effect GHG balances in two ways: 

▪  Forests absorb CO2 from the atmosphere and sequester this in biomass, which acts 

as a carbon stock. 

▪  A share of this sequestered carbon is transferred to soils through litterfall from trees 

or turned into wood products through harvesting. 

Only a share of the harvested wood ends up in  long-lived wood products, the largest 
part is used for bioenergy and paper and pulp. Besides the sequestration effect, wood 
products can use emissions savings by substituting fossil alternatives further down the 
value chain.  
Figure  21  shows  an  example  of  the  total  carbon  stock  for  a  managed  forest  and  it´s 
wood products. In the first period (60 year) the forest is mainly growing and the forest 
carbon increasing. After the first clear-cut, a significant amount of carbon is stored in 
the wood products produced from the forest, mainly for buildings. Therefore, also the 
avoided emissions by wood substitution of cement and steel are increasing. This cycle 
goes  further  on  and  captures  more  and  more  Carbon.  However,  it  is  most  important 
that  the  wood  products  remain  as  long  as  possible  in  the  building  sector/  products, 
since a burning or rotting of these products would release the Carbon again. Wood in 
buildings  and  products  that  needs  to  be  replaced  and  burned  should  be  replaced  by 
fresh wood from the forest in order to keep the carbon sink. 

June 2020  I  36 

 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 21: Total carbon stock of forest and wood products from it (Source: Forest, 
Environmental Research & Services (FERS)9) 

Wood Harvesting Scenarios 
Various models exist that project the growth and availability of wood from EU forests, 
and  scenario  outcomes  are  dependent  on  parameters  such  as  the  assumed  age 
structure  of  existing  forests,  harvesting  intensity,  rotation  period  of  to  be  planted 
forest,  forest  management  intensity,  and  climatological  conditions.  In  Annex  II  a 
baseline  is  laid  out  for  the  net  annual  increment  of  wood  and  different  scenarios  for 
the  extraction  of  wood  from  the  forest.  Summarising  and  reviewing  a  variety  of 
studies  (such  as  [G.J.  Nabuurs  et  al.,  2018;  Ragnar  Jonsson  et  al.,  2018],  [UNECE, 
2011]  ,  [Ragnar  Jonsson  et  al.,  2018]),  we  conclude  that  estimates  vary  widely 
depending  on  the  assumptions  and  boundary  conditions  that  need  to  be  met,  e.g. 
existing policies (LULUCF Regulation), demand for bioenergy, and forest management 
practices: 
▪  Bottom-up studies show that an additional 60 Mm3 may become available compared 

to the 2015 level of harvesting at 420 Mm³. 

▪  Studies that respect the limitations stipulated by the LULUCF Regulation show that 

an additional 0–140 Mm3 can be harvested towards 2050.  

▪  Studies that explore the upper limit of wood mobilisation in EU forests, while not 

letting harvests exceeding the net annual increment, show an additional potential of 
97–235 Mm³ by 2030. 

9 Source: https://www.fers.ie/forest-carbon-basic-facts/ 

June 2020  I  37 

 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Forestry Sector Impacts 

This  chapter  explores  how  much  wood  can  be  made  available  for  the  construction  of 
wooden  frames  and  building  elements,  its  impacts  on  the  forestry  sector,  and  how 
much  carbon  the  wood  can  store.  The  forestry  sector  is  relatively  complex 
economically,  with  various  residue  streams  and  recovered  products  that  need  to  be 
taken  into  account  in  the  balance.  Figure  22  illustrates  the  flows  of  woody  biomass 
and wood products for 2015 in the EU.  

Construction wood mainly relies on large diameter logs, meaning the sawn-
wood/sawmill subsector. Of the harvested wood entering that sector, around half ends 
up as a residue going to the pulp or panel industry. Wood-based construction is an 
important driver for raw material availability for pulp and paper and for emerging 
industries (such as the production WFIB for insulation purposes or wood-based 
packaging solutions), as sawmilling generates raw materials for these industries (wood 
chips, bark, sawdust, and forest residues). 

June 2020  I  38 

 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 22: Sankey diagram of the EU’s woody biomass balance in 2015                

(units in Mm3). Source: [Noemi Emanuela Cazzaniga et al., 2019] 

June 2020  I  39 

 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Wood Demand vs. Mobilisation Potential 
The  raw  material  impact  of  an  increase  in  wood  construction  can  be  estimated  as 
follows:  A  100%  market  share  of  wood  construction  of  all  buildings  in  Europe  would 
translate  to  a  maximum  direct  annual  demand  of  around  45–145  million  m3  of  wood 
products, which then translates into around 100-400 million m³ of raw wood, strongly 
depending  on  the  raw  material,  species,  production  technique,  and  product  (sawn-
wood needs to be produced from log-wood, while glulam or CLT, OSB, MDF, and WIFB 
can also be produced from smaller logs and thinning) [Elias Hurmekoski, 2017]10. 

Cross-Laminated Timber 
CLT,  glulam,  OSB,  and  WFIB  are  the  primary  wood  products  used  for  modern  wood 
construction . A CLT panel consists of several layers of dried lumber boards stacked in 
alternating  directions,  bonded  with  adhesives  and  pressed  to  form  a  solid,  straight, 
rectangular  panel.  An  advantage  of  using  CLT  is  that  the  large  diameter  logs  can  be 
used,  as  well  as  the  thinnings.  Pre-commercial  and  regular  thinning  are  forest 
management activities aimed at maintaining forest health, and the harvested wood is 
generally used for bioenergy purposes. However, using thinnings as a resource for CLT 
production  can  increase  revenue  from  thinnings  and  improve  the  economic  feasibility 
of  forest  management.  CLT  is  typically  made  from  Norway  spruce.  However,  there  is 
growing  interest  in  and  research  on  use  of  locally  abundant,  under-utilised  timber 
resources  for  which  there  are  no  established  structural  properties  as  feedstocks  for 
CLT. Examples include the use of Sitka spruce in Scotland and Ireland; Italian marine 
pine  in  Sardinia;  and  European  beech  in  Germany  and  Switzerland  [Colin  M.  Rose  et 
al., 2018]. 

Wooden Buildings as a Carbon Sink 
Wood  weighs  500  kg/m3  on  average  and  is  made  up  of  close  to  50%  carbon.11  This 
implies that 1 m3 of wood contains around 250 kg C, or 917 kg CO2. If we assume that 
wooden  construction  reaches  a  market  volume  of  50  million  Mm  [proHolz  Austria, 
2019]  of  long-lived  wooden  products,  4.6  MtCO2  would  be  locked  into  wooden 
construction  elements  annually.  This  is  a  figure  for  all  of  Europe;  however,  market 
potential  varies  per  region.  Table  7  illustrates  that  Northern  Europe  has  the  highest 
market  potential  for  additional  wood  construction,  whereas  Southern  and  Eastern 
Europe have the lowest potential. This potential is based on local culture and structure 
of  the  construction  sector  and  aligns  well  with  the  relative  amount  of  harvests 
foreseen  in  e.g.  the  EFSOS  study  elaborated  in  the  chapter  on  Wood  Harvesting 
Scenarios. 

10 The EU building stock is renewed at a 1% annual rate – an area of 240 million m2 is built annually1 . The 
wood use intensity of wood construction can be assumed to vary from 0.2 m3 /m2 (light frame) to 0.6 m3 
/m2 (massive frame). Thus, a simple calculation suggests that 100% of the European construction markets 
could be covered with 45–145 million m3 of wood products, translating to around 100-400 million m3 of raw 
wood  (the  conversion  factor  to  roundwood  equivalent  (RWE)  ranging  from  2.0  for  sawnwood  to  2.8  for 
cross-laminated timber (CLT)). As the increment in forests available for wood supply was 769 million m3 in 
2010 in EU27 (Eurostat), a 100% market share of wood construction in Europe would require a maximum of 
53% of the annual growth of European forests. 

June 2020  I  40 

 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Table 7: Market potential of wood construction in selected regions in Europe12 
Central 
Europe 
the UK 

Northern 
Europe 

Western 
Europe 

Southern  and 
Eastern 
Europe 

Region 

and 

Market 
potential 
2030 

Countries 

by 

High 

Intermediate 

Low 
intermediate 

to 

Low 

Finland, 
Norway, 
Sweden 

Austria, 
Northern  Italy, 
Southern 
Germany, 
Switzerland, 
the UK 

The 

France, 
Ireland, 
Netherlands, 
Northern 
Germany 

Czech 
Republic, 
Hungary, 
Poland, 
Southern  Italy, 
Spain 

Upper limit and bandwidth of GHG Emission Reduction  
This  chapter  shows  the  impact  of  higher  wooden  building  market  shares  (within  the 
new building rate of the European Buildings sector) that go beyond of an 3% increase 
per year as defined in the baseline scenario. A theoretical ad hoc potential is described 
in  a  first  step.  It  answers  the  question,  “What  would  happen  if  the  wooden  buildings 
market  share  would  increase  to  100%  next  year”?  Since  this  is  not  possible  in 
practice, additional boundary conditions, constraints, and elements are discussed in a 
second  step  that  brings  down  a  possible  increase  of  the  wooden  building’s  quota. 
Finally,  step  three  defines  a  realistic  upper  limit  for  the  development  of  wooden 
buildings and the bandwidth of possible GHG emission reductions by wooden buildings. 

Ad Hoc GHG Savings Potential 

To quantify the ad hoc potential of wooden buildings, the wood market share for new 
residential  and  non-residential  buildings  is  set  from  5.5%  in  2020  to  100%  in  2021. 
The  effect  would  be  94  Mt  of  CO2  stored  in  wood  products  (CO2  storage  or 
sequestration  effect),  where  55  Mt  would  be  created  by  sawn-wood  (as  glulam  or 
CLT), 32 Mt by insulation material (mainly WFIB and MDF), and 7  Mt by OSB boards 
for  wood  frame  constructions  (see  Figure  23).  The  positive  GHG  emissions  from  the 
production of wooden buildings account for 16.6 Mt, but at the same time the and the 
substitution  of  mineral  construction  variants  saves  of  89.4  Mt.  Therefore,  the 
substitution  effect  accounts  to  73  Mt.  Together  with  the  CO2-sequestraton,  the  total 
net-effect for wooden buildings sums up to 167 Mt of GHG emissions.  

12 Adapted from Elias Hurmekoski, 2017 

June 2020  I  41 

 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 23: GWP SAVINGS of wooden building material vs. conventional for new 
buildings in the EU – AD HOC POTENTIAL (Source: Legep & BEAM² Modelling) 

For  this  theoretical  ad  hoc  potential,  a  significant  amount  of  wood  would  be  needed. 
Apart  from  60  Mm³  for  sawn-wood  (glulam  and  CLT),  35  Mm³  would  be  needed  for 
wooden  insulation  material  (WFIB  and  MDF)  and  in  addition  also  8  Mm³  for  OSB 
boards. All in all, approx. 103 Mm³ of wood. Since this is a theoretical potential, this 
amount  is  not  discussed  any  further.  The  final  demand  for  the  upper  limit  in  the 
realistic pathway is discussed in a later section. 

Additional Constraints and Boundary Conditions for the uptake of Wooden 

Buildings 

To  define  a  realistic  uptake  of  wooden  buildings  and  the  wood  market  share  for  new 
buildings across the EU, the following constraints and boundary conditions need to be 
considered. Based on this element, the upper limit of a realistic pathway is defined in 
the following chapter.  

Availability of Resources and Production Capacities  
The availability of resources from the forest sector is the key criterium of using more 
wood  in  the  building  sector.  However,  the  material  must  be  supplied  on  time  and  in 
the  appropriate  quality  to  replace  more  traditional,  mineral  construction  types  of 
buildings.  Chapter  3  concludes  that  the  estimates  of  additional  available  wood 
resources  vary  widely  depending  on  the  assumptions  and  boundary  conditions  that 
need  to  be  met  in  the  underlying  studies.  The  following  additional  capacity  is 
mentioned: 

▪  Bottom-up studies show that an additional 60 Mm3 may become available compared 

to the 2015 level of harvesting at 420 Mm3. 

▪  Studies that respect the limitations stipulated by the LULUCF13 regulation show that 

an additional 0–140 Mm3 can be harvested towards 2050.  

▪  Studies that explore the upper limit of wood mobilisation in EU forests, while not 

letting harvests exceeding the net annual increment, show an additional potential of 
97–235 Mm3 by 2030. 

13 Land Use, Land Use Change and Forestry 

June 2020  I  42 

4,90,989,416,6-5,2-4,3-94,4-77,8-150-100-50050100MineralWoodDeltaMineralWoodDelta20202021GWP (Mt CO2_eq)-167 MtCO2 storage in woodGHG over LifecycleNet-effect 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

▪  At least 60 Mm³ can be assumed available, but there may be as much as 97-235 

Mm³ by 2030. 

Apart from the resources, capacities and processes (e.g. manufacturing processes for 
CLT,  WFIB  and  OSB)  for  harvesting  and  producing  timber  (sawmills  etc.)  need  to 
ramp-up to increase the output of the products. Ramp-up times and capacities need to 
be considered, as well  as the  capacity in the construction sector (craftsman) and the 
availability of planners for wooden buildings. 

Cost  
Apart  from  technical  aspects  and  the  availability  of  the  construction  material, 
manufacturing costs play an important role for the attractivity and possible uptake of 
wooden buildings. A construction costs analysis with the LEGEP14 software tool shows 
that manufacturing costs for wood building constructions are not more expensive than 
for  traditional  mineral  constructions  (see  Figure  24).  Prefabrication  and  efficiency 
improvements in manufacturing processes may also have an impact to bringing down 
cost. 
However, some external costs are not included in the alternative mineral construction 
types  (brick,  stone,  concrete),  since  carbon  emissions  are  only  factored  into  a  small 
extent (via the EU-ETS). If carbon prices are increasing, prices of mineral construction 
types will grow faster than the prices of wooden buildings.  

Figure 24: Manufacturing costs for SFH, MFH and Office building                              

(Source: Legep Modelling) 

Regulatory Policy and Fire Safety 
Regulatory  policy  is  another  criterium  for  realising  more  buildings  with  wooden 
constructions. The areas of fire safety regulation and federal building regulation define 
which  type  of  construction  material  is  allowed  for  what  purpose  in  what  kind  of 
buildings.  For  example,  it  may  not  be  allowed  to  use  combustible  materials  in 
multifamily  buildings  or  high-rise  buildings  for  the  facade  cladding  (or  at  least,  not 
only  this  material).  Whether  wood  as  structural  material  or  cladding  is  allowed  to  be 
used  is  dependent  on  the  local  and  federal  building  regulations.  Since  these 
regulations are updated on a regular basis and research findings with regard to wood 
as construction material are also input to these processes, the potential for large and 
tall buildings made of wood is growing. 

Acceptance and Individual Preferences  
In  addition  to  the  availability  of  wood  as  material,  the  availability  of  planners  and 
craftsman  is  an  important  driver  or  barrier  for  wooden  buildings.  The  individual 
preferences of building owners and acceptance aspects are also relevant to the uptake 
of the wood quota.  

14  Construction  cost  are  calculated  and  shown  for  Germany,  based  on  real  project  costs  over  the  years 
(Legep approach). 

June 2020  I  43 

Manufactoring Costs SFHmanufact. costsmanufact. costs€/m2€/NGFSolid Wood (SW)2.101359.199Wood Frame (WF)2.170371.121Brick (BR)2.076355.048Sand-Limestone (SL)2.111361.034Cellular Concrete (CC)2.322397.137 Manufactoring Costs MFHmanufact. costsmanufact. costs€/m2€/NGFSolid Wood (SW)1.130863.018Wood Frame (WF)1.165890.193Brick (BR)1.133865.391Sand-Limestone (SL)1.087830.658Reinforced Concrete (RC)1.290985.632 Manufactoring Costs Officemanufact. costsmanufact. costs€/m2€/NGFSolid Wood (SW)1.5509.671.000Sand-Limestone (SL)1.5479.656.000Reinforced Concrete (RC)1.63910.229.000 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Since the discussion about  environmental impacts and climate  change is accelerating 
more  and  more  in  society,  sustainable  construction  methods  and  materials  with  little 
(or even negative) GHG footprints will attract more and more people in the future. In 
the  in-depth  analysis  of  the  [European  Commission,  2018;],  the  EC  sees  circular 
economy  as  essential,  enabling  us  to  reach  net-zero  GHG  by  2050.  Wood  as  a 
construction  material  can  be  used  in  a  circular  economy,  while  most  of  the  mineral 
and traditional building materials are not able do so (since often recycling in the sense 
of downcycling is possible only). This factor has significant potential to accelerate the 
use of wood as construction material. 

Construction Time and Potential of Prefabrication 
The  ability  for  prefabrication  of  wooden  building  elements  is  an  advantage  compared 
to  traditional  onsite  mineral  building  constructions  (such  as  concrete  or  stone/brick). 
The construction time is much shorter due to pre-manufacturing offsite (and therefore 
the building is ready much earlier) and the quality is typically higher or easier to reach 
with  manufacturing  indoors  in  the  industry  environment.  Furthermore,  cost  decrease 
effects due to economy of scale are likely to happen if the wood market share keeps 
increasing.  

Limits of Conventional Mineral Construction Types and Materials and Climate 
Targets 
There is no way to stick to the mineral construction methods of today (and the past) if 
the construction sector is going reach climate targets. The main reason for this is that 
during the manufacturing of cement (as part of concrete and mortar), more than 50% 
of the GHG emissions do not occur due to the energy input to the process, but due to 
chemical processes in the materials production.  

Realistic  Pathway:  Additional  GHG  Savings  Through  an  Uptake  of  Wooden 
Buildings 

Based  on  the  theoretical  potential  of  wooden  buildings  for  new  residential  and  non-
residential  houses  across  the  EU  and  the  additional  constraints  and  boundary 
conditions  to  increase  the  wood  quota,  a  realistic  pathway  is  developed  to  show  the 
bandwidth  of  possible  uptakes  and  their  impacts  with  regard  to  the  GWP  in  terms  of 
GHG  emissions.  The  realistic  pathways  is  defined  by  the  baseline  as  lower  limit  and 
the upper limit as maximum realistic uptake. 

The  GHG  emissions  savings  for  wooden  buildings  in  the  upper  limit  pathway  are 
calculated based on the new building rates and assumptions for the upper limit of the 
wood  quotas.  They  consist  of  the  substitution  effect  of  wooden  buildings  (replacing 
mineral building constructions) and the CO2 storage effect of wood. 

New Building Rates and Wood Quota 
The new building rate is considered the same as for the baseline scenario, based on a 
recent  Navigant  study,  [Esser  et  al.,  2019]  which  is  0.7%  in  average  for  residential 
buildings and 1.1% for non-residential buildings.  

The wood building market share in the EU can be approximated with 5.5% of all new 
buildings  in  2020  and  a  growth  rate  of  wooden  buildings  of  3%  p.a.  since  2000. 
Compared to the baseline, where the same growth rate is assumed until 2020, a more 
ambitious definition the wood market share leads to the upper limit pathway. Here the 
market share is increased steadily towards 75% by 2050, based on a growth rate that 
is  increasing  towards  15%  p.a.  by  2031  and  then  falls  again  (see  Figure  25).  Only 
75% of the heated new non-residential buildings are covered in the calculation, since 
they  can  be  approximated  with  the  office  reference  buildings.  The  remaining  25%  of 
heated non-residential and all non-heated non-residential buildings are not covered by 

June 2020  I  44 

 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

the  calculation.  The  yearly  increase  of  the  wood  market  share  is  ambitious,  but  also 
realistic.  The  additional  constraints  and  boundary  conditions  allow  for  such  a  growth 
rate  as  upper  limit,  and  similar  developments  have  been  observed  and  assumed  for 
modelling  in  a  study  of  heat  pump  potentials  with  the  EU  market  [Bettgenhäuser  et 
al., 2013]. These assumptions lead to the new building rates and wood quotas, shown 
in Figure 26. 

Figure 25: Wood market share for new buildings and it´s growth rate – baseline and 
upper limit pathway (Source: BEAM² Modelling) 

Figure 26: New building rates for residential and non-residential buildings in the EU                                                                               

and corresponding wood market shares – baseline and upper limit pathway      

(Source: BEAM² Modelling) 

While the share of wood frame buildings is constant in the baseline with 75% within all 
wooden buildings, it decreases by 2.5% p.a. in the upper limit pathway until it reaches 
50%  for  wood  frame  constructions  and  50%  for  solid  wood  construction  types.  The 

June 2020  I  45 

 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

assumption  of  the  replaced  building  types  (mix  of  mineral  building  constructions)  is 
the same as for the baseline.  

GHG Emissions for Upper Limit Pathway 
Based  on  the  new  building  activities  for  residential  and  non-residential  buildings,  the 
wood  market  share  and  the  replaced  building  construction  types,  the  GHG  emissions 
from  new  buildings  in  the  upper  limit  pathway  are  calculated.  Figure  27  shows  the 
GWP over time for the upper limit pathway. The underlaying wood market share starts 
with 5.5% in 2020 and increases up to 75% by 2050. By than year 11.6 Mt of CO2_eq 
emissions would be emitted for the wooden buildings.  

Figure 27: GWP for new wooden buildings in the EU – upper limit (Source: Legep & 
BEAM² Modelling) 

If the same share of buildings were realised as traditional, mineral buildings as defined 
before,  significantly  more  GHG  would  be  emitted  (see  Figure  28).  Here  the  brick, 
stone,  and  concrete  construction  materials  account  for  73  Mt  of  CO2_eq  emissions  by 
2050.  

The  difference  from  the  CO2_eq  emissions  for  wooden  buildings  and  the  replaced 
construction  types  (mix  of  mineral  constructions)  is  the  substitution  effect  of  wood. 
Figure 29 shows this  effect and the corresponding savings  over time for the baseline 
and  upper  limit  scenarios,  where  the  10  Mt  CO2_eq  emissions  can  be  saved  in  the 
baseline and 62 Mt CO2_eq emissions in the upper limit pathway. The area in between is 
considered to be the realistic bandwidth of future development for wooden buildings.  

June 2020  I  46 

 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 28: GWP for new mineral buildings (replacement) in the EU – upper limit 
(Source: Legep & BEAM² Modelling) 

Figure 29: GWP SAVINGS by substitution effect of new wooden buildings in the EU – 
baseline and upper limit (Source: Legep & BEAM² Modelling) 

In  addition  to  the  substitution  effect,  the  CO2  storage  effect  of  wood  is  also  very 
relevant.  Figure  30  shows  the  CO2  savings  due  to  the  carbon  capture  and  storage 
(CCS) in wooden buildings over time.  

June 2020  I  47 

 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 30: GWP (only CO2) SAVINGS by storage effect of new wooden buildings in the 
EU – baseline and upper limit (Source: Legep & BEAM² Modelling) 

The order of magnitude of effect is comparable with the substitution effect. The wood 
must be conserved as material as long as possible, since the thermal usage or rotting 
of it would release the CO2 back into the atmosphere. However, since the substitution 
effect  alone  is  significant,  wooden  buildings  would  be  very  useful  even  without  any 
savings in the material. 

Adding  up  both  effects  leads  to  Figure  31.  By  substituting  mineral  construction 
materials  and  storing  CO2  in  the  wooden  structure  of  the  buildings,  145  Mt  of  CO2_eq 
can be saved by 2050. 

Figure 31: GWP for Substitution and Storage Effect of wood vs. mineral building 
material for new buildings in the EU – upper limit (Source: Legep & BEAM² Modelling) 

June 2020  I  48 

-160-140-120-100-80-60-40-200GWP (Mt CO2_eq)Total Mt CO2_eq -Substitution Effect and Storage Effect -upper limitCO2-Storage in wood - total potential Mt - upper limitDifference in Substitution Effect - upper limit-160-140-120-100-80-60-40-20-145 Mt 
 
 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

The  same  development  is  shown  in  Figure  32,  but  in  another  visualisation.  For  the 
years  2020,  2030,  2040,  and  2050,  the  baseline  and  upper  limit  GHG  emissions  are 
shown  for  both  mineral  buildings  materials  (to  be  replaced)  and  wooden  buildings 
materials.  The  delta  between  the  two  variants  is  shown  in  each  last  column.  The 
picture  for  2050  shows,  that  in  the  upper  limit  pathway  73.7  Mt  CO2_eq  emissions 
would  be  created  by  mineral  construction  types  (for  75%  of  the  new  building  rate, 
which  is  considered  as  realistic  upper  limit  for  the  wood  buildings  market  share  by 
2050),  while  by  that  time  the  wooden  buildings  mix  would  only  emit  11.6  Mt  CO2_eq 
emissions.  This  leads  to  a  difference  of  62.1  Mt  CO2_eq  emissions  between  the  two 
options  (substitution  effect),  which  is  significant.  If  the  CO2  storage  in  wood  is  also 
considered,  additional  savings  of  83.6  Mt  CO2_eq  occur  (storage  effect).  Both  effects 
sum  up  to  overall  savings  of  about  145.7  Mt  CO2_eq  by  2050.  Compared  against  the 
current  GHG  emissions  in  the  EU  buildings  sector  without  construction  activities  (see 
chapter  2.3.3)  of  about  650  Mt  CO2_eq,  the  145  Mt  represent  approximately  20%,  a 
significant number. 

June 2020  I  49 

 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 32: GWP of conventional building materials vs. wood over the Life Cycle         

for new buildings in the EU (Source: Legep & BEAM² Modelling) 

June 2020  I  50 

4,90,96,811,71,31,99,342,41,76,712,973,72,411,6-5,3-4,4-13,6-83,6-11,2-71,9-100-80-60-40-20020406080100BaseUpperBaseUpperBaseUpperBaseUpperBaseUpperBaseUpperBaseUpperBaseUpperBaseUpperMine-ralWoodWood-netMineralWoodWood-netMineralWoodWood-netMineralWoodWood-netGWP (Mt CO2_eq)GWP of Conventional Building Materials vs. Wood for New Buildings in the EUCO2 storage in woodGHG over LifecycleNet-effect-145 Mt2020203020402050Legend:Wood: GWPof buildings towards a 75% wood market share for new buildings (5.5% in 2020, 13% by 2030, 45% by 2040, 75% by 2050)Mineral: Corresponding GWP of the same buildings as "wood", but in mineral construction Wood-net: Net GWP of wooden buildingsBase: BaselineUpper: Upper limit pathway-62 MtPositive GHG Emissions (GWP)Negative GHG Emissions (GWP) 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Wood Demand for upper limit pathway 
To enable the uptake of wooden buildings to a market share of 75% for new buildings 
by 2050, a  significant amount of additional  resources is  requited, as  shown in  Figure 
33.  The  demand  increases  from  current  levels  around  5  Mm³  p.a.  towards 
approximately  90 Mm³ of  addition wood resources in the upper limit pathway by 
2050. This overall number contains solid wood constructions (using mainly CLT), wood 
frame constructions (using mainly glulam and OSB) and wooden insulation (WFIB and 
MDF). This amount seems reasonable, since studies show the upper limit of additional 
sustainable  wood  resources  from  EU  forests  with  a  range  of  60–235  Mm3  by  2030 
(see chapter 3), and more wood could be made available for saw-wood and further on 
usage as glulam or CLT from the existing use-cascade.  

Figure 33: Total demand of wood for buildings (solid wood, wood frame, wood fibre 
insulation and OSB/MDF boards) for new buildings in the EU – upper limit (Source: 
Legep & BEAM² Modelling) 

Depending on the type of wood product, manufacturing technique, and wood-input, a 
conversion  factor  to  roundwood  equivalent  (RWE)  ranging  from  1.5.  to  2.8  for 
different  wooden  products  (such  as  CLT,  OSB,  glulam,  WFIB)  is  assumed,  see  [Elias 
Hurmekoski, 2017]. This market share could be brought further down, since CLT and 
glulam can also be assembled by smaller log-wood pieces and many of the remaining 
parts (thinning) can be processed to WFIB or OSB, which are also needed in wooden 
buildings. 

Discussion 
The  current  new  building  rate  across  Europe  is  about  0.7%  for  residential  and  1.1% 
for non-residential buildings, while the wood market share is approx. 5.5% in average 
(with  significant  differences  between  MS),  where  wood  is  the  main  construction 
material (main products are sawn-wood, glulam, CFL, OSB and WIFB).  
The  historic  growth  rate  of  wooden  buildings  is  with  3%  p.a.  quite  moderate  and 
therefore  assumed  for  the  baseline  pathway  with  a  final  market  share  of  13%  by 
2050. This is conservative assumption, but in line with the definition of a baseline. The 
impact  with  these  amounts  of  wood  is  GHG  savings  of  about  21.6  Mt  in  2050 
compared  to  the  current  mineral  building  construction  mix.  In  relation  to  the  current 

June 2020  I  51 

 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

GHG emissions for the use phase of buildings with approx. 650 Mt CO2 across the EU, 
these savings are important – but not large.  
Since the additional potential of the EU forest sector for wood is quantified in a range 
of  60  Mm²  -  235  Mm³,  there  is  sufficient  room  for  additional  wooden  building 
constructions.  Furthermore,  the  relatively  large  share  of  wood  going  into  thermal 
usage  needs  to  be  reviewed,  since  a  long-term  material  use  of  it  is  from  a  climate 
perspective much more favourable. 
In  order  to  significantly  increase  the  share  of  wooden  buildings,  a  development  such 
as  the  upper  limit  pathway  would  be  required.  Here  the  wood  market  share  is 
increased towards 75% of the new building rate by 2050. This leads to GHG savings of 
about  61.4  Mt  GHG  emissions  for  the  substitution  effect  (replacing  mineral  materials 
with wood) and 84 Mt of CO2 that is in addition stored in wood. In total 145 CO2_eq can 
be  saved  by  2050  in  the  upper  limit  pathway  compared  to  mineral  building 
constructions.  To  support  this  development,  90  Mm³  of  wood  resource  would  be 
needed  in  2050.  In  light  of  the  additional  resources  from  EU  forests,  this  amount 
seems  to  be  reasonable  if  the  forest  and  wood  industry  as  sufficient  time  and  a 
planning horizon to manage growing material flows year by year.  
The substitution effect of wood is modelled for 2020. It is not taken into account, that 
energy mix etc. decarbonize over the coming decades. Therefore, the impact of wood 
as  material  will  become  smaller  in  the  future.  However,  energy  supply  is  only  one 
component  within  the  GHG  emissions  of  mineral  buildings  construction.  Other 
components such as process emissions cannot be avoided for current processes (such 
as cement production). If alternative materials are developed and partly could replace 
the traditional mineral materials, the impact of wood as substitute is decreasing.  
Apart from the substitution and storage effect of wood, also the forest sector can have 
an impact. If wood demand is increasing, the rather mature European forests stock is 
used as material step by step and old/mature trees are replaced by new, fast growing 
trees  which  absorb  more  CO2  than  the  mature  trees  would  do.  As  effect,  the  overall 
carbon  stock  in  the  forest  sector  can  be  increased.  However,  cutting  down  old  trees 
and forests needs to be done in a careful manner, since they also have a function to 
stabilize the climate. In hot summers, old trees vaporize a lot of water, which leads to 
a significant cooling  effect not only in the local context, but also to the  overall mean 
temperature. Cutting down old forest to substitute mineral buildings in large quantities 
therefore is not recommended, but rather finding a balance between what is the best 
way  for  the  overall  ecosystem.  Furthermore,  the  species  of  trees  will  change  due  to 
climate  change  and  long  dry  periods  during  summertime.  This  also  needs  to  be 
considered in the overall approach.  
Not  only  solid  wood,  but  also  wood  fibre  insulation  boards  (WFIB)  could  be  used  to 
replace conventional materials (such as mineral wool, EPS or XPS). For new buildings 
it  is  considered  in  the  analysis  above,  but  for  renovation  activities  there  is  a  huge 
additional potential. This makes also sense from the resource perspective, since wood 
fibre  insulation  can  also  be  produced  from  small  pieces  of  wood  –  while  sawn-wood 
only  can  be  produced  from  larger  logs.  But  also,  glulam  or  CLT  products  help  to  use 
more  of  the  resource  wood  in  wooden  products,  since  smaller  pieces  can  be  put 
together into larger elements.  
Finally,  there  are  a  couple  of  advantages  of  wooden  buildings  in  contrast  to 
conventional construction types. As wooden elements are prefabricated in an industry 
environment,  quality  assurance  and  dimensional  accuracy  are  typically  higher  or 
easier to archive in comparison to on-site constructions with stones or concrete. Since 
the construction times are minimal on site for wooden constructions, the building can 
be  occupied  earlier.  In  case  of  retrofits,  large-scale  renovations  with  prefabricated 
elements can be conducted with using wood in structure and for insulation to replace 
conventional mineral retrofits. 

June 2020  I  52 

 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

EU Policy Analysis and Recommendations 
In  order  to  be  able  to  deploy  the  potential  of  sustainable  and  renewable  materials 
(such  as  wood)  in  the  construction  sector,  the  policy  framework  needs  to  be  aligned 
with  the  overall  targets  of  a  net-zero  economy  in  the  long-term  perspective. 
Therefore, this chapter gives a brief overview on the EU building sector regulation and 
policy framework with a focus of wood as construction material. Based on this, direct 
and  indirect  wood  construction  policies  are  identified  and  further  improvement  steps 
towards a fair evaluation of the entire lifecycle for buildings are discussed.  

Key Policy Recommendations 

▪  The EU policy framework does only consider the use phase of buildings, but not the 

manufacturing/construction an disposal/reuse phase.  

▪  Therefore, the major advantages of wood as construction material are not considered. 

▪  Environmental taxes or emission trading schemes as indirect policies can help to 

stimulate the market for sustainable construction material. 

▪  Phasing out of subsidies for fossil fuel and resources would accelerate alternative 

materials. 

▪  Prohibition of certain substances or byproducts have the potential to increase the uptake 

of wooden buildings. 

▪  Market incentives but also mental models towards wooden products is important. 

▪  Subsidies and persuasion are important for countries with low wooden quotas. 

▪  The encouragement of reliable and international certification schemes to reduce quality     

and sustainability concerns is key. 

▪  Education and knowledge transfer about wood use in construction is key to overcoming 

path dependencies, which are especially strong in the building sector where the market is 
dominated by stone materials. 

▪  R&D support for innovations is a key element of a more sustainable economy; resource 

efficiency gains in Europe are mainly driven by changing technology. 

Overview of the current EU Building Regulation  
The current EU policy framework for the building sector is mainly based on the Energy 
Performance  of  Buildings  Directive  (EPBD).  But  also  other  directives,  guidance 
documents  and  schemes  are  relevant  and  have  impact  on  buildings,  such  as  the 
Energy  Efficiency  Directive  (EED),  the  Ecodesign  Directive,  the  Renewable  Energy 
Directive (RED) and the EU-ETS.  

As  central  policy  instrument,  the  EPBD  [EPBD,  2017]  sets  a  number  of  requirements 
for  new  buildings  and  (major)  renovations  across  the  EU.  Minimum  performance 
requirements  are  established  on  component  level  for  new  buildings  and  renovations, 
while  cost-optimality  is  the  leading  principle  to  set  overall  minimum  performance 
levels for new buildings and renovations. Furthermore, new buildings need to comply 
with  the  nearly  Zero  Energy  Building  (nZEB)  definition.  While  minimal  component 
performance  requirements  are  set  on  EU  level,  nZEB  definitions  and  cost-optimality 
requirements  are  assessed  and  defined  on  member  state  (MS)  level.  In  addition,  MS 
are  also  obliged  to  develop  long-term  renovation  strategies  for  their  buildings  stocks 
that comply with the long-term energy and climate targets.  

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    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

However,  all  requirements  within  the  EPBD  address  the  use  phase  of  buildings, 
excluding  the  manufacturing/construction  and  disposal/reuse  phases  of  building 
elements.  Therefore,  the  major  benefits  of  wood  as  construction  material  –  as  
discussed above – are not covered by this piece of legislation.  

The  Ecodesign  Directive  [EC,  2015]  covers  more  than  40  product  groups  and  sets 
mandatory  ecological  requirements  for  energy-using  and  energy-related  products, 
including  construction  materials  and  technical  building  systems  (TBS).  The  directive 
aims  at  reducing  the  energy  consumption  and  other  negative  environmental  impacts 
of  products  during  their  use  phase.  Manufacturers  have  to  take  mandatory 
requirements  in  the  design  stage  of  products  into  account.  While  the  Directive's 
primary aim is to reduce energy use, it is also aimed at enforcing other environmental 
considerations  including  materials  use;  water  use;  polluting  emissions;  waste  issues 
and  recyclability.  However,  also  the  Ecodesign  Directive  focuses  on  the  energy 
consumption  in  the  use  phase  of  produces,  but  does  not  include  the  manufacturing 
phase.  Since  some  preparatory  studies  for  Ecodesign  also  include  an  LCA  already, 
further steps towards a full life cycle approach should be possible, especially in view of 
TBS (which are not considered in the analysis above). 

The amended Energy Efficiency Directive [European Parliament and the Council of the 
European  Union  (EU)  2018]  is  also  relevant  for  the  building  sector.  It  updates  the 
policy framework to 2030 and beyond and sets an overall mandatory energy efficiency 
target for 2030 of at least 32.5%. Thereby it sets indirect incentives to reduce energy 
consumption (and GHG emissions) during the manufacturing and construction process 
of buildings outside the building sector. 

Also,  the  EU  Emission  Trading  System  (EU-ETS)  has  an  impact  of  the  construction 
sector across Europe. The total  amount  of  certain greenhouse gases to be  emitted is 
limited  by  a  cap,  while  the  emission  allowances  within  the  system  can  be  traded 
between companies. Since the price of GHG emissions is expected to grow and energy 
intense industries (such as cement) receive free allocations at the moment, the impact 
on industry processes can potentially  grow.  

Finally,  the  review  of  the  Construction  Product  Regulation  (CPR)  and  the  published 
Circular  Economy  Action  Plan  of  the  European  Commission  aim  for  a  strategy  of  a 
sustainable  built  environment.    The  sustainability  performance  of  construction 
products is addressed in the context of the revision of the CRP , including the possible 
introduction of recycled content requirements for certain construction products. 

Identify Options to Promote Wood Construction 
Based  on  the  current  EU  building  regulations  the  following  chapter  focuses  on  the 
identification of options to promote wood as construction material within the EU policy 
framework.  The  analysis  is  based  on  [Jakob  Hildebrandt  et  al.,  2017]  to  a  large 
extent,  since  the  authors  worked  on  a  comprehensive  summary  of  EU  policies 
regarding  wooden  buildings.  The  focus  is  on  the  identification  of  possibilities  for  the 
consideration of wood construction EU building sector regulation. In this regard, three 
trends  in  development  can  potentially  lead  to  a  higher  share  of  wood  construction  in 
the future: 

▪  Technical progress towards high performing load-bearing wood constructions 

▪  Progress in the harmonization of fire protection and environmental regulations  

▪  Constant growth in the capacity to produce ecological construction materials 

June 2020  I  54 

 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Against  this  background,  it  can  be  distinguished  between  indirect  and  direct  wood 
construction  policies  (see  Figure  34).  The  following  chapters  elaborate  on  the 
possibilities how to align the policy framework to promote wood construction. 

Figure 34 Categorisation of wood construction policies.                                          

Source: [Jakob Hildebrandt et al., 2017]. 

Indirect wood construction policies 
In  contrast  to  direct  policies,  the  indirect  wood  construction  policies  address  the 
framework and boundary conditions around the construction sector. One the one hand 
side  instruments  can  indirectly  influence  rates  of  new  construction  or  retrofitting  by 
increasing  costs  for  consumption  of  environmentally  harmful  products.  Promotion  of 
fiscal  reforms,  development  of  environmental  taxes,  and  development  of  emission 
trading schemes are instruments that restrict carbon-intense products and production 
processes—supporting  ecological  construction  products.  It  is  debatable  whether 
current carbon pricing schemes are effective at reducing carbon emissions because the 
increasing efficiency in the manufacturing sector is mainly driven by energy costs and 
less by policies. Under Europe’s current legislation, the cement sector – a high carbon 
emission sector – will not have to buy carbon certificates until 2043 (and, as such, the 
amount of carbon produced by the sector will probably not decrease).  

On  the  other  hand  phasing  out  of  subsidies  that  support  fossil  resources  can  in 
addition can foster a sustainable building sector as well. Finally, command and control 
instruments (such as prohibiting the use of certain substances or byproducts) have the 
potential to increase the uptake of wooden building materials. 

In  this  framework,  one  the  one  hand  side  subsidies  and  other  support  for  the  use  of 
fossil  energy  and  materials  should  be  phased  out,  while  at  the  same  time 
environmentally friendly taxes and emission trading systems should be established on 
the  other  hand  to  support  an  increase  of  wooden  building  constrictions  on  the  mid- 
and long-term. 

Direct Wood Construction Policies  

On the other hand, policy instruments can directly influence rates of new construction 
or  retrofitting  by  enhancing  wood  construction  processes  and  products  as  well  as 
supporting  the  wood  construction  resource  base.  In  this  filed  also  overcoming 
prejudices is quite important: “People generally regard wood as less fire resistant, less 
durable,  less  dimensionally  stable,  less  resistant  to  decay  and  insects,  and  more 
expensive  to  maintain,  than  other  materials.”  As  these  arguments  are  generally  not 
valid  and  a  closer  look  is  needed  to  take  specific  parameters  of  individual  materials 
into  account,  the  public  should  be  informed  about  it.  Furthermore,  experiences  with 

June 2020  I  55 

 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

building  standards  and  tradition  have  a  great  influence  on  the  willingness  to  take  up 
alternative materials such as wood components (wooden window frames). 

In  countries  with  low  wooden  construction  rates,  also  subsidies  and  persuasion  are 
suitable instruments to familiarize consumers to these new products. On the one hand 
knowledge  transfer  from  producer  and  politics  to  consumer  through  labelling  or 
information campaigns is important, but on the other hand also between producers. 

The  encouragement  of  reliable  and  international  certification  schemes  to  reduce 
quality  and  sustainability  concerns  regarding  the  increased  use  of  wood  (demands  of 
different  groups  such  as  architects,  designers,  building  owners)  also  should  be 
addressed.  Certification  often  includes  compatibility  with  strict  fire  regulation 
standards. Education and knowledge transfer about wood use in construction is key to 
overcoming  path  dependencies,  which  are  especially  strong  in  the  building  sector 
where the market is dominated by stone materials. The uptake of innovative wooden 
construction  components  depends  not  only  on  market  incentives  but  also  on  the 
mental  models  towards  wooden  products  in  the  construction  sector.  R&D  support  for 
innovations is a key element of a more sustainable economy; resource efficiency gains 
in  Europe  are  mainly  driven  by  changing  technology.  Support  can  be  public  and 
private through innovative financing instruments, such as revolving funds, preferential 
interest  rates,  guarantee  schemes,  risk-sharing  facilities,  blending  mechanisms. 
Finally,  the  public  procurement  can  be  designed  in  such  way,  that  sustainable 
materials  are  supported  or  at  least  all  external  effects  (such  as  environmental 
impacts) are considered.  

All  in  all,  direct  wood  construction  policies  need  to  enable  higher  wooden  market 
shares for new buildings and renovations. Prejudices must be overcome, and positive 
examples  and  experience  need  to  be  spread.  Non  the  less  international  (mandatory) 
certification schemes help to clearly  shown the benefits  of sustainable materials  over 
the entire life cycle. Regulatory policy can also help to support this development, if not 
only  the  use  phase  of  buildings  would  be  covered  by  building  sector  specific 
regulation,  but  the  entire  life  cycle  of  a  buildings  including  manufacturing, 
construction, disposal and recycling. 

Discussion  
The  current  building  and  construction  policies  on  EU  level  do  cover  the  use  phase  of 
buildings very well, while the manufacturing and construction phase on the one hand 
and  the  disposal  and  recycling  phase  on  the  other  hand  are  not  covered.  Therefore, 
the  major  advantages  of  wooden  constructions  and  building  elements  are  not 
considered in this scope. Environmental taxes or emission trading schemes as indirect 
policies  can  help  to  stimulate  the  market  for  sustainable  construction  material, 
supported by a phasing out of subsidies for fossil fuel and resources. In addition, the 
prohibition  of  certain  substances  or  byproducts  have  the  potential  to  increase  the 
uptake of wooden buildings further. Education and knowledge transfer about wood as 
well  as  showing  positive  examples  and  focusing  on  R&D  are  key  elements  for  the 
success of wooden buildings.  

The  way  forward  form  a  policy  perspective  should  be  focused  on  creating  a  level 
playing field for all buildings materials, also including TBS. If impact assessments are 
done  over  the  full  life  cycle,  a  fair  comparison  between  alternatives  is  possible  with 
regard  to  energy  and  climate  targets.  Once  the  individual  footprints  are  clear, 
instruments like environmental taxes and emission trading systems with fair boundary 
conditions  can  significantly  help  to  bring  sustainable  building  materials  forwards.  In 

June 2020  I  56 

 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

addition  to  that,  direct  subsidy  measures  can  help  in  markets  with  very  low  wood 
shares to reach a critical mass and to accelerate the system. 

June 2020  I  57 

 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Conclusions 
The scope of the building sector typically only covers the use stage (B) of the building, 
while  the  product/construction  stage  (A),  disposal/end-of  life  stage  (C)  and  recycling 
potential stage (D) are also important from a lifecycle perspective. In this regard, the 
LCA  of  individual  buildings  highlights,  that  mineral  buildings  have  significantly  higher 
material  stream with higher mass  streams than wooden buildings  - which impact the 
GWP of the construction. The impact assessment shows, that the GWP over the for the 
manufacturing  and  construction  for  wooden  buildings  with  minimal  2  kg  CO2_eq/m2 
compared to mineral buildings with up to 500 kg CO2_eq/m2 is marginal. Apart from the 
temporary CO2-saving effect (CCS) of wood (917 kg CO2/m³) – which is not included 
in  the  numbers  above  -  the  substitution  effect  of  mineral  materials  accounts  for  the 
largest part of the overall GWP.  

The  current  wood  market  share  for  new  residential  and  non-residential  buildings  is 
approx. 5.5%, while the new building rate for residential buildings is about 0.7% and 
1.1%  for  non-residential  buildings.  Where  wood  is  the  main  construction  material, 
sawn-wood,  glulam,  CFL,  OSB  and  WIFB  are  mostly  used  as  products.  The  baseline 
pathway builds on a future growth rate for wooden buildings of 3% p.a. as it has been 
observed in the past decade. The impact with these amounts of wood is GHG savings 
of  about  21.6  Mt  in  2050  (assuming  todays  energy  mix  and  processes)  compared  to 
the current mineral building construction mix. In relation to the current GHG emissions 
for the use phase of buildings with approx. 650 Mt CO2 across the EU, these  savings 
are  important  –  but  not  large.  An  ambitious  pathway  towards  using  wood  in  the  EU 
building sector is described in the upper limit pathway. Here the wood market share 
is increased towards 75% of the new building rate by 2050. This leads to GHG savings 
of  about  61.4  Mt  GHG  emissions  for  the  substitution  effect  (replacing  mineral 
materials with wood) and 84 Mt of CO2 that is in addition stored in wood. In total 145 
CO2_eq can be saved by 2050 in the upper limit pathway compared to mineral building 
constructions.  To  support  this  development,  90  Mm³  of  wood  resource  would  be 
needed  in  2050.  In  light  of  the  additional  resources  from  EU  forests,  this  amount 
seems  to  be  reasonable  if  the  forest  and  wood  industry  as  sufficient  time  and  a 
planning  horizon  to  manage  growing  material  flows  year  by  year.  If  wood  would  be 
reused as often as possible and - if not – replaced by fresh wood from the forest, the 
net-sink and carbon stock of wooden building would remain over time. 

In  the  area  of  EU  policy  framework,  the  current  building  and  construction  policies  on 
EU  level  do  cover  the  use  phase  of  buildings  very  well,  while  the  manufacturing  and 
construction phase on the one hand and the disposal and recycling phase on the other 
hand  are  not  covered.  In  this  setting,  the  benefits  of  wooden  buildings  are  not 
accounted  for  in  the  current  system.  From  the  policy  side,  emission  trading  schemes 
or  environmental  taxes  can  help  to  establish  a  level  playing  field  when  externalities 
are considered over the whole life cycle of a product. Furthermore, the phasing out of 
fossil  subsidies  is  an  important  element  to  remove  market  distortion.  In  order  to 
support this process, direct subsidy measures can help in markets with very low wood 
shares to reach a critical mass and to move the market forward.  

Since there is sufficient evidence about the positive impacts of wooden buildings in the 
EU building sector, the next steps need to be prepared now. Fair market conditions, a 
level  playing  field  and  assessments  over  the  total  lifecycle  of  products  –  also 
considering the ability to work into a circular economy – need to be implemented. This 
also includes a definition of the buildings sector that goes beyond the current scope. 

June 2020  I  58 

 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Further Research Questions 
In  order  to  further  specify  the  findings  and  add  elements  to  them,  the  following 
further  research  questions  (nonexclusive)  arise  from  the  study.  In  the  authors  view 
they should be addressed by further research. 

Methodology  

▪  Dynamic calculations with regard to a dynamic/shifting baseline can help to further 
specify the findings. The GHG emissions of replaced materials is decreasing over 
time due to decreasing carbon content in electricity mix and process improvements 
over time. This is an important element that should be considered. 

▪  How could a methodology look like that includes LCA /embodied carbon into cost-
optimality calculations  and minimum performance requirements for buildings? 

▪  What is the potential of the growing insulation market for energetic retrofits of 

buildings and the possible role of wooden insulation (WFIB)?` 

Forest 

▪  What impacts does a shift in tree-species due to climate change have on the 

availability of resources from the forest (growth time until maturity) and on the 
carbon content captured by the trees over time? 

▪  How does the cooling effect of old/mature forests change if mature trees cut down 
and replaced by young, fast growing trees? What is a reasonable balance to not 
eliminate the cooling effect of forests on the climate, especially during summertime? 

Policy and Co-Benefits 

▪  What changes in regulations are needed to remove barriers for wooden buildings 

(especially MFH, office)? 

▪  What would be the price impact of increasing carbon tax on conventional 

construction methods versus wooden constructions? 

▪  What would be the options for introducing “emission certificates” for wooden 

buildings to create additional financial market incentives? 

▪  What is the impact of wooden buildings on health compared to “conventional” 

buildings? 

▪  How should a policy setup look like that supports sustainable materials? 

Market and Costs 

▪  What would be the potential of cost-reductions in case of upscaling of industrial built 

wooden buildings? 

A  more  detailed  analyses  of  necessary  changes  to  the  market  could  help  to  better 
understand  the  next  steps  (industrial  capacity,  workforce    in  forestry,  industry, 
construction site, designers, planners etc.) 

June 2020  I  59 

 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Abbreviations 

BR 

Brick 

cbm 

cubic meter 

CO2 

Carbon dioxide 

CO2_eq  Carbon dioxide equivalent 

CC 

Cellular Concrete 

CCS  Carbon Capture and Storage 

CLT  Cross-laminated Timber 

EED  Energy Efficiency Directive 

EPBD  Energy Performance of Buildings Directive 

EPD   Environmental Product Declaration 

EU-ETS 

EU Emission Trading System 

GHG  Greenhous-Gas  

GWP  Global Warming Potential 

IA 

Impact Assessment 

LULUCF 

Land Use, Land Use Change and Forestry 

MDF  Medium Density Fibre Board 

MFH  Multifamily House 

MS 

Member State (of the EU) 

OSB  Oriented Strand Board 

RED  Renewable Energy Directive 

RC 

Reinforced Concrete 

SFH  Single-Family House 

SL 

Sand-Limestone 

SW 

Solid Wood 

TBS 

Technical Building Systems 

WF  Wood Frame 

WFIB  Wood Fibre Insulation Board 

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    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

REFERENCES 
Altenbach, Holm (2018): Holzmann/Meyer/Schumpich Technische Mechanik. Festigkeitslehre. 13th 

ed.: Springer Vieweg. 

Bettgenhäuser, Kjell; Offermann, Markus; Boermans, Thomas; Bosquet, Michelle; Grözinger, Jan; 
Manteuffel, Bernhard von; Surmeli, Nesen (2013): Heat Pump Implementation Scenarios until 
2030. An analysis of the technology's potential in the building sector of Austria, Belgium, 
Germany, Spain, France, Italy, Sweden and the United Kingdom. By order of European Heat 
Pump Association (EHPA). ECOFYS. Berlin, Cologne (BUIDE12080)Bettgenhäuser, Kjell; 
Offermann, Markus; Boermans, Thomas; Bosquet, Michelle; Grözinger, Jan; Manteuffel, 
Bernhard von; Surmeli, Nesen. 

Colin M. Rose; Dan Bergsagel; Thibault Dufresne; Evi Unubreme; Tianyao Lyu; Philippe Duffour; 
Julia A. Stegemann (2018): Cross-Laminated Secondary Timber: Experimental Testing and 
Modelling the Effect of Defects and Reduced Feedstock Properties Colin M. Rose; Dan 
Bergsagel; Thibault Dufresne; Evi Unubreme; Tianyao Lyu; Philippe Duffour; Julia A. 
Stegemann. 

DESTATIS (2019): Baugenehmigungen von Wohn- und Nichtwohngebäuden nach überwiegend 

verwendetem Baustoff - Lange Reihen z. T. ab 1980 DESTATIS. 

Dietmar Walberg; Oliver Brosius; Thorsten Schulze; Antja Cramer (2015): Massiv- und Holzbau bei 
Wohngbäuden. Vergleich von massiven Bauweisen mit Holzfertigbauten aus konstenseitiger, 
bautechnischer und nachhaltiger Sicht. Arge Kiel Dietmar Walberg; Oliver Brosius; Thorsten 
Schulze; Antja Cramer. 

EC (Ed.) (2015): Ecodesign - Energy efficient products. European Commission (EC). Available online 
at http://ec.europa.eu/energy/efficiency/ecodesign/eco_design_en.htm, accessed 8/24/2015. 

EC (2017): Level(s) Factsheet. EC, DG Env EC. 

Elias Hurmekoski (2017): How can wood construction reduce environmental degradation? 

European Forest Institute Elias Hurmekoski. 

EN 15804 (2014): EN 15804 - Sustainability of construction works - Environmental product 

declarations EN 15804. 

2014: EN 15804 - Sustainability of construction works - Environmental product declarations. 

EN ISO 14040 (2009): EN ISO 14040 Environmental management - LCA - Principles and framework 

EN ISO 14040. 

2009: EN ISO 14040 Environmental management - LCA - Principles and framework. 

DIN EN ISO 14040, November 2009: Environmental management - Life cycle assessment - 

Principles and framwork. 

EPBD (2017): AMENDMENT PROPOSALS. On the proposal for a Directive of the European 

Parliament and of the Council amending Directive 2010/31/EU on the energy performance of 
buildings - Proposal for a Directive (COM(201 6) 765 final – 2016/0381 (COD)). 

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Esser, Anne; Dunne, Allison; Meeusen, Tim; Quaschning, Simon; Wegge, Denis; Hermelink, 

Andreas et al. (2019): Comprehensive study of building energy renovation activities and the 
uptake of nearly zero-energy buildings in the EU. Final report - Infographics. Research report 
prepared for European Commission, DG Energy. Ipsos; Navigant Esser, Anne; Dunne, Allison; 
Meeusen, Tim; Quaschning, Simon; Wegge, Denis; Hermelink, Andreas; Schimschar, Sven; 
Offermann, Markus; John, Ashok; Reiser, Marco; Pohl, Alexander; Grözinger, Jan. 

European Commission (2018;): Our Vision for A Clean Planet for All: Social Transition European 

Commission. 

European Commission (EC) (2018): A Clean Planet for all. A European strategic long-term vision for 
a prosperous, modern, competitive and climate neutral economy. Communication from the 
Commission to the European Parliament, the European Council, The Council, The European 
Economic and Social Committee, the Committee of the Regions and the European Investment 
Bank. COM(2018) 773 final. 

European Commission (EC) (2019): The European Green Deal - Building and renovating. European 

Commission (EC) European Commission (EC). 

European Parliament and the Council of the European Union (EU) (2018): Directive (EU) 

2018/2002 of the European Parliament and of the Council of 11 December 2018 amending 
Directive 2012/27/EU on energy efficiency. EED. In: Official Journal of the European Union, vol. 
61 (L 328), pp. 210–230. 

G.J. Nabuurs; E.J.M.M. Arets; J.-P. Lesschen; M.J. Schelhaas (2018): Effects of the EU-LULUCF 

regulation on the use of biomass for bio-energy G.J. Nabuurs; E.J.M.M. Arets; J.-P. Lesschen; 
M.J. Schelhaas. 

Jakob Hildebrandt; Nina Hagemann; Daniela Thrän (2017): The contribution of wood-based 

construction materials for leveraging a low carbon building sector in europe Jakob Hildebrandt; 
Nina Hagemann; Daniela Thrän. 

JRC (2017): Level(s) – A common EU framework of core sustainability indicators for office and 
residential buildings. Parts 1 and 2: Introduction to Level(s) and how it works. JRC JRC. 

Klauß, Swen; Kirchhof, Wiebke (2010): Entwicklung einer Datenbank mit Modellgebäuden für 

energiebezogene Untersuchungen, insbesondere der Wirtschaftlichkeit. Report by order of the 
German Federal Ministry of Transport, Building and Urban Development (BMVBS) and the 
German Federal Institute for Research on Building, Urban Affairs and Spatial Development 
(BBSR). Edited by Zentrum für Umweltbewusstes Bauen e.V. Kassel Klauß, Swen; Kirchhof, 
Wiebke. 

Maschinenbau-Wissen.de: Biegewiderstandsmoment für einfache Querschnittformen berechnen 

Maschinenbau-Wissen.de. Available online at http://www.maschinenbau-
wissen.de/skript3/mechanik/balken-biegung/210-biegewiderstandsmoment1, accessed 
10/4/2019. 

DIN EN 15804:12 + A1:2013, Julie 2014: Nachhaltigkeit von Bauwerken - 

Umweltproduktdeklarationen - Grundregeln für die Produktkategorie Bauprodukte; 

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Noemi Emanuela Cazzaniga; Ragnar Jonsson; Daniele Palermo; Andrea Camia (2019): Sankey 
diagrams of woody biomass flows in the EU-28. JRC Noemi Emanuela Cazzaniga; Ragnar 
Jonsson; Daniele Palermo; Andrea Camia. 

proHolz Austria (2019): WOOD AND CLIMATE. pro Holz Austria proHolz Austria. 

Ragnar Jonsson; Viorel NB Blujdea; Giulia Fiorese; Roberto Pilli; Francesca Rinaldi; Claudia 

Baranzelli; Andrea Camia (2018): Outlook of the European forest-based sector: forest growth, 
harvest demand, wood-product ,markets, and forest carbon dynamics implications Ragnar 
Jonsson; Viorel NB Blujdea; Giulia Fiorese; Roberto Pilli; Francesca Rinaldi; Claudia Baranzelli; 
Andrea Camia. 

DIN EN 15978: Sustainability of construction works - Assessment of environmental perfomance of 

buildings - Calculation method, accessed 7/25/2019. 

The European Parliament and the Council of the European Union (2018): European Parliament 

legislative resolution of 17 April 2018 on the proposal for a directive of the European 
Parliament and of the Council amending directive 2010/31/EU on the energy performance of 
buildings (COM(2016)0765 – C8-0499/2016 – 2016/0381(COD)). EPBD. 

UNECE (2011): European Forest Sector Outlook Study II. UNECE UNECE. 

Wegener,  Gerd;  Pahler,  Andreas;  Tratzmiller,  Michael  (2010):  Bauen  mit  Holz  = 
aktiver Klimaschutz. Technische Universität München Wegener, Gerd; Pahler, Andreas; 
Tratzmiller, Michael. 

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Annex  I  -  Analysis  of  individual  Buildings:  Detailed 

Input and Outputs 

Reference Buildings (LCA stage I) 
The follwing chapters give an overview on the geometries of the reference buildings  

Reference Building “Single-Family House” 
The SFH reference building is a detached,  rectangular shaped building with a pitched 
roof oriented to the south. The area of the pitched roof can be used to collect the solar 
irradiation  via  solar  panels  to  substitute  parts  of  the  primary  energy  demand  with 
renewable  energy.  The  building  has  2+1  storeys,  a  basement,  a  ground  floor  and  a 
top  floor  (see  Figure  35  and  Figure  36).  The  basement  is  excluded  from  the  thermal 
envelope. The living area adds up to 147m². The building is designed for a four-person 
household and has 3 bedrooms.  

Key facts 

Location 

Type 

Roof 

Cologne, 
Germany 

Detached SFH 

Pitch roof 

Number of floors 

2+1 (basement) 

Residents 

Orientation 

Number of apartments 

Average apartment size 

Gross floor area 

Gross Volume 

4 

South 

1 

147 

233 

788 

     m² 

m² 

m³ 

Figure 35: Side and front view of the SFH model building 

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Figure 36: View on chapter and ground floor plan of the SFH model building 

Furthermore,  the  building  is  equipped  with  an  air-to-water  heat  pump  for  space 
heating and hot tap water.  

Reference Building “Multi-Family House” 
The MFH reference building is a detached, rectangular shaped building with a flat roof 
and south orientation. The area of the flat roof can be used for the installation of a PV-
system.  The  building  has  5+1  storeys  and  can  accommodate  25  residents  in  12 
apartments.  The  basement  is  excluded  from  the  thermal  envelope  and  is  about  two-
thirds of the size of each of the other floors. The living area amounts to  880 m², see 
Figure 37 and Figure 38. 

Key facts 

Location 

Type 

Roof 

Cologne 

Detached 

Flat roof 

Number of floors 

5+1(basement) 

Residents 

Orientation 

Number of apartments 

Average apartment size 

Gross floor area 

Gross Volume 

25 

South 

12 

73 

1.290 

3.663 

     m² 

m² 

m³ 

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Figure 37: Side and front view of the MFH model building 

Figure 38: View on chapter and ground floor plan of the MFH model building 

The  MFH building is also  equipped with a air-water heat pump  for  space heating and 
hot tap water.  

Reference Building “Office” 
The office building is a detached, u-shaped building with a flat roof, see Figure 39. The 
builing  has  no  basement  (other  than  the  residential  reference  buildings)  and  each  of 
the three storeys has the same structure, see Figure 40: Group offices (zone 2), open-
plan  office  (zone  3),  meeting  and  seminar  rooms  (zone  4),  WC  and  snitary  facilities 
(zone 16), common area (zone 17) and hallways (zone 19). 

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Key facts 

Location 

Type 

Roof 

Number of floors 

Orientation 

Gross floor area 

Gross Volume 

Cologne 

Detached 

Flat roof 

3 

South 

6998 

24146 

m² 

m³ 

Figure 39: Side and front view of the office building 

Figure 40: View on chapter and ground floor plan of the office building 

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The entire roof can be used for a PV-system. Solar irradiation is collected to substitute 
parts of the primary energy demand with renewable energy. Also the office building is 
equipped with an air-water heat pump for space heating and hot tap water.  

Building Construction Variants and Materials (LCA stage I) 
The thickness of the load-bearing layers of all wall constructions have been defined in 
consultation  with  experts.  The  statics  of  the  timber-frame  variant  have  been 
calculated  in  some  more  detail  due  to  its  complex,  loadbearing,  wooden  structure. 
Based  on  the  current  building  practice,  the  three  most  relevant  mineral  buildings 
materials  are  vertically  perforated  bricks,  sand-lime  bricks  and  reinforced-
concrete/cellular concrete.  

Basement 
Regardless of the selected construction material for a building, the basement structure 
usually consists  of  reinforced  concrete. However, their thickness  strongly depends  on 
the soil and the construction material. The choice of lightweight construction, such as 
wood  frame  construction,  leads  to  an  enormous  reduction  in  the  total  weight  of  a 
building. The cellar walls can be built thinner due to the reduced weight of the overall 
construction.  However,  wooden  buildings  receive  the  same  foundations  as  mineral 
buildings, which consist of concrete and whose dimensioning depends  on the bearing 
capacity of the building ground.  
For  this  study  all  calculations  concerning  the  basement  structure  were  chosen  to  be 
equally thick as the focus lies on the primary construction over ground. The basement 
components  have  the  same  impact  on  the  LCA  of  all  considered  model  buildings  and 
can be neglected.  
The layers of the foundation are as follows (from the inside out): 

Table 8: Layers of the foundation for each model building 

Number  Component 

Thickness  

1 

2 

3 

4 

5 

6 

7 

Tiles and tile adhesives 

  1,0 cm 

Cement screed + bitumen paper 

  5,0 cm 

Impact  sound  insulation  (mineral 
wool) 

  1,5 cm 

Thermal 
(mineral 
insulation 
wool)  +  sealing  made  of  glass 
fleece 

  5,0 cm 

Reinforced concrete 

25,0 cm 

Subbase 
barrier (PE-foil) 

(concrete)  +  vapour 

  7,5 cm 

Insulation 
(XPS-insulator) 
Separating layer (geotextile) 

+ 

  8,0 cm 

Total 

53,0 cm 

The layers of the cellar walls are as follows (from the inside out): 

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Table 9: Layers of the cellar walls for each model building 

Number 

Component 

Thickness  

1 

2 

3 

4 

5 

Synthetic  resign  dispersion  + 
reinforced concrete 

25,0 cm 

Cement mortar 

  2,0 cm 

Waterproofing 
sheets) 

(bitumen 

  0,6 cm 

Perimeter 
insulator) 

insulation 

(XPS-

20,3 cm 

Cement plaster + lime-cement 
plaster 

  2,3 cm 

Total 

50,2 cm 

Exterior Wall Structures  

The  exterior  walls  built  the  biggest  portion  of  the  building  envelope.  Thereby,  they 
have  a  big  impact  on  the  energy  balance,  the  mass  balance  and  consequently  the 
GHG-balance  of  a  building.  Due  to  the  size  of  the  MFH,  the  thickness  of  the  load-
bearing structure had to be adjusted for solid wood and wood frame variants. For the 
brick  and  sand-limestone  the  thickness  of  the  load-bearing  structure  is  sufficient  to 
carry the weight of both the SFH and the MFH. 

Variant 1 – Solid Wood  

a) 
The load bearing construction of solid wood walls consist of continuous solid material. 
It  is  comparable  to  concrete  and  brick  walls  of  conventional  buildings.  However,  the 
specific density of wood is significantly lower than of conventional building materials.  
The layers of the solid wood wall are as follows: 

Figure 41: Layered structure of variant 1 – Solid wood wall [LEGEP] 

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Table 10: Components of wall SFH 

Thickness 

Number 

Component 

EFH 

MFH 

Office 

1 

2 

3 

Board stacking wall 

18,0 cm 

22,2 cm 

20,3 cm 

Wood-fibre insulation board 

14,0 cm 

13,0 cm 

13,0 cm 

Substructure 
(coniferous timber) 

+ 

cladding 

  7,5 cm 

  7,5 cm 

  7,5 cm 

Total 

39,5 cm 

42,7 cm 

40,8 cm 

Due to the number of storeys of the MFH (and also the office building), the lower three 
levels must be stronger than the two top floors. Therefore, an average value  of 22,2 
cm of the bearing layer of the exterior walls is assumed for the calculations (see Table 
11). To keep the U-value of 0,18 W/m²*K the insulation thickness had to be reduced 
accordingly. Nevertheless, the wall structure itself stays the same.  

Table 11: Detailed and average thickness of the loadbearing layer of the MFH exterior 
wall 
Thickness 

Storey 

1 

2 

3 

4 

5 

25,0 cm 

25,0 cm 

25,0 cm 

18,0 cm 

18,0 cm 

Table 12: Detailed and average thickness of the loadbearing layer of the Office 
exterior wall 
Thickness 

Storey 

1 

2 

3 

25,0 cm 

18,0 cm 

18,0 cm 

b) Variant 2 – Wood Frame Construction 
Typical and economic  construction grids  for wood frame  construction are  vertical and 
horizontal  beam  spacings  of  625  mm.  They  are  based  on  the  standard  format  of 
planking  material.  The  format  of  many  insulating  materials  is  also  matched  to  these 
grids. Considering the right choice of beam size, the static of a building can always be 
achieved within this construction grid.  
The model buildings are constructed in this specific construction grid. The beam size of 
the supporting framework of the SFH, the MFH and the office building differ from each 
other due to the different size of the buildings and the different number of storeys. On 

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account  of  the  five  storeys,  the  pressure  at  the  support  points  must  be  taken  into 
account for dimensioning the supporting framework. To  ensure the statics, the beam 
size must be as shown in Table 13.  

Table 13: Detailed and average beam size of the MFHs exterior wall 

Storey 

Thickness [cm] 

Average [cm] 

1 

2 

3 

4 

5 

24/24 

24/24 

18/24 

12/24 

12/24 

18/24 

For the calculations of the MFH and the office building an average beam size, resulting 
from the actual beam sizes of the different storeys, is being considered. The insulation 
thickness  had  to  be  adopted  accordingly.  The  layers  of  the  wood  frame  wall  are  as 
follows: 

Figure 42: Layered structure of variant 2 - Wood frame construction [LEGEP] 

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Table 14: Components of wall variant 2 

Thickness 

Number 

Component 

SFH 

MFH 

Office 

1 

2 

3 

4 

5 

Plasterboard  

  1,2 cm 

  1,2 cm 

  1,2 cm 

Facing 
(coniferous 
insulation (flax) 

shell  with  beams 
+ 
wood) 

frame 

construction 
Wood 
(coniferous 
timber)  with 
insulation  (flax)  +  planking 
(OSB)  

Thermal 
insulation 
fibre insulation board) 

(wood 

  5,0 cm 

  5,0 cm 

  5,0 cm 

16/18 cm 

18/24 

18/24 

10,0 cm 

13,0 cm 

13,0 cm 

Plaster (lime-cement) 

  0,5 cm 

  0,5 cm 

  0,5 cm 

Total 

32,65 cm 

30,9 cm 

30,9 cm 

c) Variant 3 – Vertically Perforated Bricks 
The  type  of  brick  for  this  wall  construction  is  a  vertically  perforated  brick  with 
integrated  perlite  insulation.  The  brick  itself  provides  a  good  insulation  value. 
Combined  with  perlite  filled  perforations,  no  further  insulation  on  the  outside  is 
necessary to reach the desired U-value. Due to its load-bearing capacity the vertically 
perforated brick as shown in Table 15 is suitable for both, the SFH and the MFH. Bricks 
are not considered for Office buildings. The layers of the brick wall are as follows: 

Figure 43: Layered structure of variant 3 – Bricks [LEGEP] 

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Table 15: Components of wall variant 3 

Number  Component 

Thickness 
(EFH 
MFH) 

+ 

1 

2 

3 

Internal plaster 

  1,0 cm 

Vertically  perforated  brick  + 
perlite  insulation  +  lime-cement 
mortar 

49,0 cm 

Exterior plaster (lime-cement) 

  1,5 cm 

Total 

51,5 cm 

d) Variant 4 – Sand-Limestone 
The  sand-limestone  has  no  perforation.  Sufficient  insulation  is  provided  by  a  thermal 
insulation composite system on the outside of the wall. Due to its physical properties, 
the sand-limestone with the specified wall thickness (see Table 16) is suitable for SFH, 
MFH and the Office building.  

Figure 44: Layered structure of variant 4 - Sand-limestone [LEGEP] 

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Table 16: Components of wall variant 4 

Number  Component 

Thickness  

1 

2 

3 

4 

Woodchip  wallpaper  +  paste  + 
gypsum plaster 

  1,5 cm 

Sand-lime  brick  +  lime-cement 
mortar 

24,0 cm 

Thermal 
wool) 

insulation 

(mineral 

20,0 cm 

Plaster (lime-cement) 

  0,6 cm 

Total 

46,1 cm 

e) Variant 5 – Reinforced concrete/ Cellular concrete 
The concrete building structure consits of similar layers as the sand-linestone, but only 
with 20cm of reinforced concrete instead of the stone, see properties in Table 17. With 
its  propeerties  the  wall  structure  is  suitable  for  MFH  and  the  office  buildings  (not 
relevant for SFH).  

Table 17: Components of wall variant 5a – reinforced concrete 

Number  Component 

Thickness  

1 

2 

3 

4 

Woodchip  wallpaper  +  paste  + 
gypsum plaster 

  1,5 cm 

Reinforced concrete 

20,0 cm 

Thermal insulation (EPS) 

20,0 cm 

Plaster (lime-cement) 

  0,6 cm 

Total 

42,1 cm 

Table 18: Components of wall variant 5b – cellular concrete 

Number  Component 

Thickness 
(EFH 
MFH) 

+ 

1 

2 

3 

Internal plaster 

  1,0 cm 

Cellular  concrete  +  lime-cement 
mortar 

49,0 cm 

Exterior plaster (lime-cement) 

  1,5 cm 

Total 

51,5 cm 

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For cellular concrete, the properties are shown in  

Table 18. They are quite similar to the layers for perforated bricks, since no additional 
insulation is required for the target energy efficiency level.  

Storey Ceilings 
In  the  following  subchapters,  the  structure  of  the  storey  ceilings  considered  in  this 
study are presented. 

Variant 1 – Solid Wood 
The loadbearing layer of the solid wood construction consists of bonded board stacking 
elements. 

Figure 45: Layered structure of variant 1 – Solid wood 

The layers of the solid wood ceiling are as follows: 

Table 19: Components of ceiling variant 1 

Number 

Component 

Cork parquet 

Thickness  

  0,6 cm 

1 

2 

3 

4 

5 

Cement screed + bitumen paper 

  5,0 cm 

Impact sound insulation (mineral 
wool) 

  2,0 cm 

Planking (OSB) 

Board stacking ceiling 

  1,9 cm 

16,0 cm 

Total 

25,5 cm 

Variant 2 – Wooden Beams 
The  beam  size  of  the  loadbearing  ceiling  construction  depends  on  the  area  to  be 
bridged. For this purpose, the storeys of the model buildings are divided into chapters. 
For each chapter, the beam size is determined individually. The average beam size for 
the ceilings of the model buildings is height/width (h/w) = 8/24 cm (see  Table 20). It 
is used for the calculations of this thesis and can be applied to the SFH, the MFH and 

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the  office  building.  The  geometric  height  of  the  beams  always  exceeds  their  width, 
because it increases the bending resistance moment15. 

Figure 46: Layered structure of variant 2 – Wooden beams 

The layers of the wooden beams ceiling are as follows: 

Table 20: Components of ceiling variant 2 

Number 

Component 

Cork parquet 

Cement screed + bitumen paper 

Thickness  

  0,6 cm 

  5,0 cm 

1 

2 

3 

4 

5 

6 

7 

Impact sound insulation (Mineral wool) 

  2,0 cm 

Planking (flat pressed board) 

  2,2 cm 

Insulation  (Sheep  wool)  +  trickle  protection 
(Kraft paper) 

10,0 cm 

Wood frame construction (coniferous timber) 

8/24 cm 

Mounting  (Steel  and  coniferous  timber)  + 
suspended ceiling (gypsum plasterboard) 

  4,0 cm 

Total 

33,8 cm 

Variant 3, 4 and 5 – Concrete 
In  mineral  construction,  ceilings  generally  consist  of  concrete.  For  that  reason,  the 
ceilings  of  the  vertically  perforated  brick  construction  and  the  sand  lime  brick 
construction are the same. Concrete has a high load-bearing capacity and good impact 
sound properties. 

15  The  bending  resistance  moment  (also  axial  resistance  moment)  is  required  for  the  calculation  of 
mechanical  stresses  under  bending  load.  It  can  be  used  to  determine  the  stiffness  and  deflection  of 
geometric bodies under certain loads. An essential factor for the level of the bending resistance moment is 
the  geometry  of  the  beam  cross-chapter  and  also  the  direction  of  the  bending  load  [Altenbach,  2018; 
Maschinenbau-Wissen.de]. 

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Figure 47: Layered structure of variants 3, 4 and 5 – concrete 

The layers of the concrete ceiling are as follows: 

Table 21: Components of ceiling variants 3, 4 and 5 

Number 

Component 

Thickness  

1 

2 

3 

4 

Floor boards (coniferous timber) 

  2,3 cm 

Bearing 
timber 
(coniferous timber) 

construction 

12,0 cm 

Insulation (cellulose flakes) 

12,0 cm 

Reinforced  concrete  +  dispersion 
paint 

16,0 cm 

Total 

30,3 cm 

Roofs 
The construction of the roof is identical for each SFH variant. It reflects a state-of-the-
art construction. A good insulation is necessary for the roof of the SFH as well as for 
the roof of the MFH and offic building because the room underneath is used as living 
space.  Especially  during  the  summer  months,  the  increased  heat  transfer  of  badly 
insulated  roofs  leads  to  the  overheating  of  rooms.  A  distinction  is  made  between  the 
roofs of variant 1 – 2 and 3 – 5 of the MFH and the office building. 

Roof of the SFH  
The layers of the SFH roof are as follows: 

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Figure 48: Layered structure of the roof for all SFH variants 

Table 22: Components of the roof for all variants 
Thickness  

Component 

Number 

1 

2 

3 

4 

Visible shuttering + air sealing 

    2,4 cm 

Beams 
thermal 
flakes) 

(coniferous 
insulation 

timber)  + 
(cellulose 

40/10 cm 

Roof 
fibreboard) 

formwork 

(softwood 

    1,9 cm 

Counter  battening 
timber) 
roof 
(coniferous timber) + roof tiles 

(coniferous 
battening 

+ 

  11,0 cm 

Total 

  55,3 cm 

The entire useable surface of the roof is covered with polycrystalline photovoltaic (PV)-
modules.  The  roof  has  a  total  surface  area  of  114  m²  of  which  112  m²  are  covered 
with PV-modules. This corresponds to 80 PV-modules as the size of a single module 
is 1,4 m². The roof surface faces south and is therefore ideally positioned for the use 
of a PV-system.  Only the inclination of the pitched roof is not optimal at 12°, but due 
to the large area available it is inconsiderable. 

Roof of the MFH/Office for variant 1 – 2   
The  load-bearing  construction  of  the  flat  roof  of  the  MFH  for  variant  1  –  2  consist  of 
wooden double joists with thermal insulation in between.  

June 2020  I  78 

 
 
 
 
 
 
 
 
 
 
 
 
 
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Figure 49: Layered structure of the roof variant 1 – 2 of the MFH/Office 

The layers of the MFH/Office roof for variant 1 – 2 are as follows: 
Component 

Number 

Thickness  

1 

2 

3 

4 

5 

Planking (OSB) 

    2,0 cm 

Double joists + thermal insulation 
(mineral wool)  

  40/8 cm 

Polypropylene  fleece  +  Planking 
(OSB) 

    2,7 cm 

Planking  (coniferous  timber)  + 
separating layer (polyethylene)  

    2,5 cm 

Battening  (coniferous  timber)  + 
planking  (coniferous  timber)  + 
metal covering 

    7,0 cm 

Total 

  54,2 cm 

Roof of the MFH/Office for variant 3 – 5   
Variant 3 – 5 of the MFH/Office are completed by a reinforced concrete roof, similar to 
their ceilings.  

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Figure 50: Layered structure of the roof variant 3 – 5 of the MFH/Office 

The layers of the MFH/Office roof for variant 3 – 5 are as follows: 

Number 

Component 

Thickness  

1 

2 

3 

4 

5 

6 

Plasterboard  and  mineral  wool 
insulation 

8,0 cm 

Reinforced concrete 

25,0 cm 

Bitumen sheets + bitumen paper 

0,5 cm 

Polystyrene  rigid  foam  panels 
expanded 

20,0 cm 

Roof  sealing  (bitumen)  +  root 
with 
protection 
polyester fleece inlay 

(bitumen) 

1,0 cm 

Extensive  substrate  +  gravel  + 
vegetation 

20,0 cm 

Total 

74.0 cm 

Windows and Doors 
The  share  of  windows  and  doors  is  equal  to  each  model  building,  regardless  of  the 
construction  material.  All  windows  and  doors  are  of  identical  quality  to  each  variant. 
They have no impact on the ratio of the LCA’s result.  

The  following  chapters  give  an  overview  on  the  results  of  the  LCA  calculations  with 
regard  to  the  use  phase  (energy  balances)  and  the  construction-,  demolition-  and 
reuse-phase. 

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    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Energy Balance (LCA stage I) 
This following sub-chapters give an overview on the energy balances of the reference 
building variants.  

Single family house 
As  shown  in  the  following  table,  the  annual  primary  energy  demand  of  each  variant 
differs accordingly to the u-values of the exterior walls.  

Table 23: Annual primary energy demand and u-values of all SFH variants 

Multi-family house 

Table 24: Annual primary energy demand and u-values of all MFH variants 

Office Building 

Table 25: Annual primary energy demand and u-values of all Office variants 

Mass Balance (LCA stage II) 
This  following  sub-chapters  give  an  overview  on  the  mass  balances  of  the  reference 
building variants.  

Single family house 
The  mass  balance  of  the  variants  strongly  depends  on  the  material  used  for  the 
construction.  Since  wood  has  a  lower  density  than  mineral  construction  material,  the 
mass  of  the  two  timber  variants  is  lower  than  the  mass  of  the  two  mineral  variants 
(see  Table  26).  However,  the  ratio  between  the  share  of  mass  for  the  new 
construction and the maintenance is almost similar to each variant.  

June 2020  I  81 

Energyu-value wallu-value roofu-value winfinal energyprimary energyW/(m²K)W/(m²K)W/(m²K)kWh/(m²a)kWh/(m²a)Solid Wood (SW)0,170,170,6715,928,7Wood Frame (WF)0,170,170,6715,928,7Brick (BR)0,170,170,6716,028,7Sand-Limestone (SL)0,180,170,6716,128,9Cellular Concrete (CC)0,180,170,6716,128,9Energyu-value wallu-value roofu-value winfinal energyprimary energyW/(m²K)W/(m²K)W/(m²K)kWh/(m²a)kWh/(m²a)Solid Wood (SW)0,160,160,7115,227,3Wood Frame (WF)0,170,160,7115,427,7Brick (BR)0,170,160,7115,327,5Sand-Limestone (SL)0,180,160,7115,427,7Reinforced Concrete (RC)0,180,190,7115,427,7Energyu-value wallu-value roofu-value winfinal energyprimary energyW/(m²K)W/(m²K)W/(m²K)kWh/(m²a)kWh/(m²a)Solid Wood (SW)0,160,160,768,916,0Sand-Limestone (SL)0,180,180,768,916,0Reinforced Concrete (RC)0,170,170,768,916,0 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Table 26: Comparison of the mass of the SFH variants 

Multi-family house 
The mass of the MFH increased, compared to the SFH, exponential to its size and the 
amount of construction material used. The ratio of the mass input for new construction 
and  maintenance  increased  by  1  %  and  thereby  nearly  stayed  the  same  to  the  SFH. 
The ratios can be taken from the following table.  

Table 27: Comparison of the mass of the MFH variants 

Office Building 

Table 28: Comparison of the mass of the variants for the office building 

June 2020  I  82 

MaterialMass totalMass basementMass  above basementtttSolid Wood (SW)19712770Wood Frame (WF)19412767Brick (BR)335127208Sand-Limestone (SL)349127222MaterialSolid Wood (SW)Wood Frame (WF)Brick (BR)Sand-Limestone (SL)tm3tm3tm3tm3tm3tm3408813659--57161163313659117712661610591958410212436581591968585611310181WoodConcreteBricks, StonesInsulationSteelOSBMaterialMass totalMass basementMass  above basementtttSolid Wood (SW)666312354Wood Frame (WF)638312326Brick (BR)1.204312892Sand-Limestone (SL)1.5303121.218Reinforced Concrete (RC)1.8273141.513MaterialSolid Wood (SW)Wood Frame (WF)Brick (BR)Sand-Limestone (SL)Reinforced Concrete (RC)tm3tm3tm3tm3tm3tm3205460375165--1922036582171377167613727313345223834725331346486353344066111.022456330237674005676111.5656698158334118511WoodConcreteBricks, StonesInsulationSteelOSBMaterialMass totalMass basementMass  above basementtttSolid Wood (SW)2.64102.641Sand-Limestone (SL)6.53506.535Reinforced Concrete (RC)7.82207.822MaterialSolid Wood (SW)Sand-Limestone (SL)Reinforced Concrete (RC)tm3tm3tm3tm3tm3tm31.6753.758966425001551.7972944149902.7851.2432.6961.9365473.2684575749906.1472.6286624742703.35769490OSBWoodConcreteBricks, StonesInsulationSteel 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

LCA Impact Assessment Details (LCA stage III) 
This  following  sub-chapters  give  an  overview  on  the  life-cycle  assessment  (LCA) 
results  for the  reference building variants. In  general, the  LCA approach comprises a 
variety of environmental indicators and impact categories, but this analysis focuses on 
the Global Warming Potential (GWP) in CO2_eq GHG emissions as main indicator. 

Single family house 

Table 29: Global warming potential of the four variants of the SFH 

Multi-family house 

Table 30: Global warming potential of the five MFH variants 

Office Building 

Table 31: Global warming potential of the three Office variants 

June 2020  I  83 

GWP (EU Data)Manufacturing A1-A3Retrofit B2+B4Dsiposal    C3-C4End of LC      DGWP of SWt CO2eqt CO2eqt CO2eqt CO2eqSolid Wood (SW)-33,27,5084,80-46,20Wood Frame (WF)6,27,5036,80-23,80Brick (BR)72,57,5017,70-16,70Sand-Limestone (SL)67,97,9018,90-16,40GWP (EU Data)GWP of SWSolid Wood (SW)Wood Frame (WF)Brick (BR)Sand-Limestone (SL)totaltotalonly Manu-facturingonly Manu-facturingt CO2eqkg CO2eq/m2t CO2eqkg CO2eq/m212,975,69-33,2-193,9026,7156,116,236,2381,0473,7472,5424,0378,3458,1467,9397,32GWP (EU Data)Manufacturing A1-A3Retrofit B2+B4Dsiposal    C3-C4End of LC      DGWP of SWt CO2eqt CO2eqt CO2eqt CO2eqSolid Wood (SW)-218,734,40422,00-235,50Wood Frame (WF)-6,532,90118,00-102,70Brick (BR)320,632,6053,10-61,90Sand-Limestone (SL)318,949,6070,30-71,40Reinforced Concrete (RC)337,766,3078,40-92,20GWP (EU Data)GWP of SWSolid Wood (SW)Wood Frame (WF)Brick (BR)Sand-Limestone (SL)Reinforced Concrete (RC)totaltotalonly Manu-facturingonly Manu-facturingt CO2eqkg CO2eq/m2t CO2eqkg CO2eq/m22,22,85-218,7-286,2941,754,62-6,5-8,47344,4450,77320,6419,62367,4480,85318,9417,37390,2510,74337,7442,03GWP (EU Data)Manufacturing A1-A3Retrofit B2+B4Dsiposal    C3-C4End of LC      DGWP of SWt CO2eqt CO2eqt CO2eqt CO2eqSolid Wood (SW)-1.631,8256,643.148,31-1.756,94Sand-Limestone (SL)1.710,9266,12377,18-383,09Reinforced Concrete (RC)1.745,9342,76405,32-476,66 
 
 
 
 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

June 2020  I  84 

GWP (EU Data)GWP of SWSolid Wood (SW)Sand-Limestone (SL)Reinforced Concrete (RC)totaltotalonly Manu-facturingonly Manu-facturingt CO2eqkg CO2eq/m2t CO2eqkg CO2eq/m216,22,60-1.631,8-261,461.971,1315,831.710,9274,132.017,3323,241.745,9279,75 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Annex  II  –  Impact  of  Wooden  Building  on  EU  Building 

Sector – Details 

Methodology – The Navigant BEAM² Model 

This  section  gives  an  overview  on  the  methodology  used  for  the  ex-ante  assessment 
of policy option, which is the BEAM² model. 
Terms and Definitions 
As the Built Environment Analysis Model BEAM² model is set up in the framework 
of the European Energy Performance of Buildings Directive (EPBD), the  general  terms  
and    definitions    are    aligned  with  it.  The  relevant  document  in  that  context  is  the 
umbrella document for all European standards within the EPBD, which is the Technical 
Report  (TR):  Explanation  of  the  general  relationship  between  various  CEN  standards 
and  the  Energy  Performance  of  Buildings  Directive  (EPBD),  see  (CEN/TR  15615)16. 
They are also valid for the energy demand calculations for space heating and cooling 
from (DIN EN ISO 13790)17, which are also referred to. 
Scope 
The scope of the model is described in this section. General references for the energy-
related calculations are (CEN/TR 15615) and report by Boermans et al.18. 
The calculation methodology follows the framework set out in the Annex to the EPBD. 
For useful heating and cooling demand calculations the methodology in EN ISO 13790 
(DIN  EN  ISO  13790)  allows  a  simplified  monthly  calculation  based  on  building 
characteristics.  It  is  not  dependent  on  heating  and  cooling  equipment  (except  heat 
recovery)  and  results  in  the  heating  energy  that  is  required  to  maintain  the 
temperature  level  of  the  building.  It  can  either  be  provided  by  the  heating/cooling 
system  or  be  recovered  from  the  exhaust  air  stream.  The  calculations  are  based  on 
specified  boundary  conditions  of  indoor  climate  and  external  climate,  which  are  also 
given on monthly basis. Furthermore, information on the internal and solar heat gains 
as  well  as  transmission  and  ventilation  heat  losses  are  required.  Based  that  energy 
demand the delivered energy (final energy) for heating, cooling, hot water, ventilation 
and  lighting  if  applicable  are  calculated  per  fuel  type.  It  takes  account  of  heat 
emission,  distribution,  storage  and  generation  and  includes  the  auxiliary  energy 
demand from building-related components like fans and pumps. 

In  a  last  step  the  overall  energy  performance  in  terms  of  primary  energy  and  CO2 
emissions  is  calculated.  An  overview  of  the  calculation  process  is  given  in  Figure  51, 
based  on  the  umbrella  document  (CEN/TR  15615).  It  involves  following  the  energy 
flows from the left to the right. 

The three steps of the  energy performance calculation are always done  for reference 
buildings  for  a  sector,  age  group,  retrofit  level  and  HVAC  systems.  Subsequently  the 
energy costs per year and the investment costs in case of a new buildings or  retrofit 
are calculated.  

16  CEN/TR  15615.  Technical  Report  -  Explanation  of  the  general  relationship  between  various  European 
standards and the Energy Performance of Buildings Directive (EPBD) - Umbrella Document, CEN April 2008 
(English). 
17  DIN  EN  ISO  13790.  Energy  performance  of  buildings  -  Calculation  of  energy  use  for  space  heating  and 
cooling (ISO 13790:2008), Beuth Verlag Berlin 1999 (German version EN ISO 13790:2008). 
18  Boermans,  Thomas,  Kjell  Bettgenhäuser,  Andreas  Hermelink,  and  Sven  Schimschar.  May  2011.  Cost 
optimal  building  performance  requirements  -  Calculation  methodology  for  reporting  on  national  energy 
performance requirements on the basis of cost optimality within the framework of the EPBD, Final Report, 
European Council for an Energy Efficient Economy eceee, Stockholm (English). 

June 2020  I  85 

 
 
 
 
 
 
 
 
 
 
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Figure 51: Schematic Illustration of the scope for the newly developed Built-
Environment-Analysis-Model BEAM2, Source:(CEN/TR 15615)19 

Key for Figure 51 
(1)  represents  the  energy  needed  to  fulfil  the  users  requirements  for  heating,  cooling,  lighting  etc, 
according to levels that are specified for the purposes of the calculation. 
(2) represents the "natural" energy gains - passive solar heating, passive cooling, natural ventilation, 
daylighting ˝U together with internal gains (occupants, lighting, electrical equipment, etc) 
(3) represents the building’s energy needs, obtained from (1) and (2) along with the characteristics 
of the building itself. 
(4)  represents  the  delivered  energy,  recorded  separately  for  each  energy  carrier  and  inclusive  of 
auxiliary  energy,  used  by  space  heating,  cooling,  ventilation,  domestic  hot  water  and  lighting 
systems, taking into account renewable energy sources and co-generation. This may be expressed in 
energy units or in units of the energy ware (kg, m3, kWh, etc). 
(5) represents renewable energy produced on the building premises. 
(6)  represents  generated  energy,  produced  on  the  premises  and  exported  to  the  market;  this  can 
include part of (5). 
(7) represents the primary energy usage or the CO2 emissions associated with the building.  

19  The  figure  is  a  schematic  illustration  and  is  not  intended  to  cover  all  possible  combinations  of  energy 
supply,  on-site  energy  production  and  energy  use.  For  example,  a  ground-source  heat  pump  uses  both 
electricity and renewable energy from the ground; and electricity generated on site by photovoltaic could be 
used  entirely  within  the  building, or  it  could  be exported entirely, or  a combination of  the  two.  Renewable 
energy wares like biomass are included in [7], but are distinguished from non-renewable energy wares by 
low CO22 emissions. In the case of cooling, the direction of energy flow is from the building to the system. 

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Structure and Methodology 
The basic model setup and calculation process is shown in Figure 52 . It is based on 
the energy demand calculations for space heating and cooling from the ISO Standard 
13790:2008  (DIN  EN  ISO  13790).  As  all  calculations  are  executed  for  a  highly 
disaggregated building stock with all its characteristics, the following description of the 
methodology  and  calculation  process  applies  for  all  sub-segments  of  the  building 
sector within the model. 
Basic  input  to  the  model  are  data  on  the  building  stock  such  as  building  types,  floor 
area, age groups, retrofit levels, HVAC systems in stock and population. Furthermore, 
the climate data such as temperature and irradiation is required. Based on this data a 
status-quo inventory of the building stock can be constructed. 
For  the  scenario  analysis  as  central  part  of  the  model,  additional  input  data  with 
respect to population forecast, GDP development, new building, demolition and retrofit 
activities,  thermal  insulation  standards,  heating,  ventilation  and  air  conditioning 
equipment,  renewable  energy  systems  and  energy  efficiency  measures  is  required. 
Furthermore,  energy  costs,  cost  for  energy  efficiency  measures  at  the  building 
envelope and costs for heating, cooling and ventilation systems and renewable energy 
systems  together  with  increase  rates  and  discount  rates  are  processed.  With  respect 
to the overall energy performance the greenhouse gas emissions factors and primary 
energy factors are required per fuel type and embodied energy and GHG emissions for 
energy efficiency and HVAC systems. 
The calculation process over the scenario time frame is organized as follows. Based on 
the initial floor area distribution along the reference buildings (RB), age groups (AG), 
retrofit levels (RL), heating systems (HS)20, hot water systems (DHW)21 and cooling 
systems  (CS)  a  forecast  for  the  floor  area  is  done  taking  into  account  new  building, 
demolition and retrofit programs for all or parts of these combinations. 

20  Heating  systems  (HS)  also  include  ventilation  systems  (VS)  and  solar  thermal  systems  (STS)  for  HS 
support if applicable. 
21 Hot water systems (DHW) also include solar thermal systems (STS) for hot water if applicable. 

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Figure 52: General Structure of  the Built-Environment-Analysis-Model BEAM2 

June 2020  I  88 

 
 
 
 
 
 
 
 
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All  activities  in  year  i  have  an  effect  starting  in  year  i+1.  The  useful  energy  demand 
for  heating  and  cooling  is  derived  from  an  integrated  calculation  algorithm  based  on 
(DIN  EN  ISO  13790).  The  energy  demands  for  hot  water,  auxiliary  energy  and 
electrical appliances if applicable are also derived. The final energy is calculated based 
on  the  parameters  of  the  HVAC  systems22.  The  aggregated  final  energy  for  heating 
can  be  compared  to  top-down  data.    In  this  case  a  calibration  factor  is  calculated, 
which  can  be  applied  to  the  final  energy  for  heating.  The  delivered  energy  together 
with  the  primary  energy  and  GHG  emission  factors  are  combined  to  the  overall 
primary energy and GHG emissions. For the economic assessment heating and cooling 
loads per single building type are derived, which are relevant to the systems sizes and 
investment costs. The economic evaluation takes beside the investment costs also the 
energy  costs  into  consideration.  In  addition  to  the  above  described  output  the 
embodied  energy  and  primary  energy  for  all  energy-related  components  (efficiency 
and  HVAC  systems)  are  quantified  in  the  model  based  on  the  total  volumes  of 
insulation, area of windows and number and power of HVAC equipment. 

Scenario Results 
Main outputs of the model are the floor area developments for RB, AG, RL, HS, DHW 
and CS in the first place. Next step is the calculation of the useful energy demands for 
heating,  cooling  and  hot  water.  From  this  the  final  energy/  delivered  energy  for 
heating, cooling, hot water, ventilation and auxiliary energy is derived. For the overall 
energy  performance  the  greenhouse  gas  emissions  and  primary  energy  is  been 
calculated. Furthermore the embodied primary energy and greenhouse gas emissions 
of  the  energy  related  components  for  new  buildings  and  retrofits  are  considered.  For 
the  economic  evaluation  energy  costs  per  year  are  provided  as  well  as  investment 
costs in new buildings and retrofits.  In order to compare yearly costs the investments 
are broken down along the lifetime of components to yearly costs by use of annuities. 
All results are given in specific units (e.g. per m2 ) and for the overall building stock in 
the respective scenario. 

Input Data 
Input data to the model describes the current building stock as status-quo. This is e.g. 
the  floor  area  distribution  and  the  definition  and  specifications  of  reference  buildings 
(RB),  age  groups  (AG),  retrofit  levels  (RL)  and  HVAC  systems  such  as  heating  (HS), 
hot water (DHW), solar thermal  systems (STS), ventilation systems (VS) and cooling 
systems (CS).  
A  more  detailed  description  of  the  BEAM²  model  is  available  in  the  dissertation  by 
Bettgenhaeuser23. 

EU Forest Sector 
This chapter aims to answer the question how much timber can be extracted from the 
EU’s  forests  up  to  2050  for  the  purpose  of  building  construction,  and  how  much  of  a 
carbon  sink  this  represents.  As  such,  we  first  explain  the  dynamics  of  carbon 
sequestration  in  forests  and  products,  and  how  the  effects  are  measured. 
Subsequently,  we  discuss  the  structure  and  development  of  EU  forests  to  2030  and 
2050 under different scenarios. Finally, we discuss the conversion and end-use sector, 
focusing  on how much  of the wood  could be used  for the production  of  end-products 
like sawn-wood, cross-laminated timber (CLT), glulam, oriented strand boards (OSB), 
wood fibre insulation boards (WFIB) or medium density fibre board (MDF). 

22 The final energy is equal to the delivered energy plus energy produced in or on the building by solar or 
wind systems. 
23 Bettgenhäuser, K. (2013). Integrated Assessment Modelling for Building Stocks - A Technical, Economical 
and Ecological Analysis. Dissertation TU Darmstadt D17, Ingenieurwissenschaftlicher Verlag 2013. 

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Carbon Sequestration in Forests and Wood Products 
Before discussing the potential of the EU’s forests to supply wood for the construction 
sector,  it  is  important  to  create  a  common  understanding  of  the  dynamics  of  carbon 
sequestration in forests and products.  
Forests impact greenhouse gas balances in two ways: 

▪  Forests absorb CO2 from the atmosphere and sequester this in biomass, which 

thereby acts as a carbon stock. 

▪  A share of this sequestered carbon is transferred to soils through litterfall from trees 

or turned into wood products through harvesting. 

Carbon  sequestration  in  wooden  products  with  a  long  lifetime,  such  as  wooden 
building  frames,  delays  the  release  of  carbon  into  the  atmosphere  and  allows  the 
regrowth  of  new  forests  which  can  then  again  absorb  CO2.  Only  a  share  of  the 
harvested wood currently ends up in long-lived wood products, the largest part is used 
for  bioenergy  and  paper/pulp.24  Besides  the  sequestration  effect,  wood  products  can 
leverage  emission  savings  by  substituting  fossil  alternatives  further  down  the  value 
chain (see in-depth analysis in chapter 2).  
The  figure  illustrates  that  when  observing  only  the  forest  aspect,  harvesting  appears 
to  lead  to  carbon  losses  to  the  atmosphere.  However,  when  considering  the  entire 
wood value chain this effect is more nuanced and can lead to long-lived sequestration 
in  products  and  various  substitution  effects  that  are  higher  than  the  (temporary) 
carbon loss from the forest. 
In the past decades, European forests have shown a relatively stable rate of CO2 removals from 
the  atmosphere,  mostly  because  the  forest  area  expanded,  and  the  annual  increments  of 
available wood also increased. At the same time, wood harvesting remained stable, meaning that 
the CO2 removal rate could remain stable even though forests get older and on average take up 
less  CO2.  Although  it  is very  challenging  to maintain such  a  rate  of  CO2  removal  due  to  the  age 
structure of European forests25, proper forest management and right harvesting forests can keep 
forests vital with a steady uptake of CO2.  

24  Nabuurs  et  al.  (2018),  ‘Effects  of  the  EU-LULUCF  regulation  on  the  use  of  biomass  for  bio-energy’, 
https://library.wur.nl/WebQuery/wurpubs/fulltext/449788 
25 Older forests have shown to have lower uptake of CO2 compared to young-growth forests. 

June 2020  I  90 

 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 53: Flow diagram of carbon in a managed forest-wood products and energy 
chain.26 

Wood Harvesting Scenarios 
Various models exist that project the growth and availability of wood from EU forests, 
and  scenario  outcomes  are  dependent  on  parameters  such  as  the  assumed  age 
structure  of  existing  forests,  harvesting  intensity,  rotation  period  of  to  be  planted 
forest, forest management intensity and climatological  conditions. Below we  sketch a 
baseline  for  the  ‘net  annual  increment’  of  wood  and  different  scenarios  for  the 
extraction of wood from the forest. 

1.  In the baseline, Nabuurs et al. (2018) assume a total net annual increment of 
789 million m3 (Mm3) per year in 2015 and decreases slightly towards 2050 to 
about  777  Mm3.  This  is  the  amount  of  wood  that  could  be  theoretically 
harvested.  However,  to  protect  the  forest  carbon  stock  sustainable  harvesting 
criteria  should  be  applied,  which  would  ensure  that  the  harvesting  level  is 
below this net annual increment. 

Scenarios  outlined  by  Nabuurs  et  al.  (2018)  show  that  harvesting  removals 
could rise from 420 million m3 in 2015 to 420–560 million m3 in 2050 (Figure 
54).  All  scenarios  are  modelled  within  the  limitations  –  or  rather  possible 
interpretations  –  of  the  EU  LULUCF  Regulation.  The  LULUCF  Regulation 
stipulates  a  no-debit  target  for  every  country,  meaning  that  accounted 
emissions from land use are entirely compensated by an equivalent removal of 
CO₂ from the atmosphere through action in the sector. The level of harvesting 
very much determines the annual sink, and thus whether a country is ‘debited’. 
All  scenarios  are  modelled  within  the  limitations  –  or  rather  possible 
interpretations – of the LULUCF Regulation. 

26 Nabuurs et al. (2015), ‘A new role for forests and the forest sector in the EU post-2020 climate targets’, 
http://edepot.wur.nl/371799 

June 2020  I  91 

 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 54: Development of harvesting removals within the limitations of the 
LULUCF Regulation.  

The  effect  of  these  harvesting  scenarios  is  that  the  current  net  forest  sink  
would decrease from - 430 MtCO2 in 2015 to between -275 and -90 Mt CO2 in 
2050. The main reason for this decline is the ageing of European forests and 
the  corresponding  decline  in  forest  growth  rate,  combined  with  other  trends 
like increasing wood demand and the related rising harvesting removals.  
Despite a slight decrease of forest increment over time, in 2050 the increment 
is with 777 Mm3 still well above the total wood removals which sum up to 686 
Mm3.  Reasons  for  the  declining  forest  increment  are  a  change  in  age  class 
structure  towards  a  higher  share  of  older  forest  stands  that  grow  at  lower 
rates  and  a  saturation  of  biomass  accumulation.  European  forests  get  older 
but also thicker and therefore grow relatively slower in the future. 

2.  Less recent studies like the European Forest Sector Outlook Study II from 2011 
(EFSOS II) by UNECE also project harvesting potentials under various scenarios 
running up to 2030. The theoretical potential scenario explores the upper limit 
of  wood  harvesting  while  maintaining  the  growing  stock  of  forest.  Since  the 
purpose  of  this  study  is  to  find  the  maximum  amount  of  wood  that  could  be 
extracted  for  the  purpose  of  construction,  the  types  of  harvest  selected  are 
pre-commercial thinnings, regular stemwood thinnings and stemwood harvests. 

The net annual increment in this study increases from 744 Mm3 in 2010 to 860 
Mm3  in  2030,  which  is  higher  than  in  the  study  by  Nabuurs  et  al.    The 
combined  thinnings  and  stemwood  harvests  remain  relatively  stable  over  the 
assessment  period,  decreasing  slightly  from  657  Mm3  in  2010  to  655  Mm3  in 
2030 – thinnings decrease and regular harvests increase. Within this study it is 
not  taken  as  a  boundary  condition  that  the  forest  sink  capacity  is  protected, 
which is the case in Nabuurs et al. 
By  far  the  largest  amounts  of  harvests  in  this  study  are  concentrated  in 
Sweden, Germany, France and Finland. However, Poland, Romania and Austria 
are also important for the European wood supply, all harvesting more than 15 
Mm3 per year by 2030 with more than 10 Mm3 of thinnings. 

June 2020  I  92 

 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 55: Overview of forestry parameters in the EFSOS II scenario, 
including an estimate of sawn wood available from harvest and thinning. 

3.  Besides  the  described  studies,  other  forest  assessments  have  been  done  by 
e.g.  Jonsson  et  al  (2018)  using  the  CBM  –  GFTM  model,      the  EU  Reference 
Scenario  2016  and  ReceBio.  These  assessments  project  a  possible  harvesting 
of  517  to  616  Mm3  already  by  2030,  which  is  predominantly  driven  by 
increased  demand  for  fuelwood  for  bioenergy.  Carbon  stocks  are  often 
significantly  affected  in  these  studies  due  to  the  higher  harvesting  intensities 
which would lead to issues in complying with the LULUCF Regulation. As stated 
in the introduction, this may still be beneficial to do from a climate perspective 
since  this  carbon  taken  out  of  the  forests  is  stored  in  the  ‘harvested  wood 
products’ pool and potentially leveraged to  substitute more  emission intensive 
products. 

4.  Finally,  the  SIMWOOD  project  should  be  mentioned,  which  aimed  to 
demonstrate how the unused potential of European forests can be mobilised in 
a  sustainable  way,  i.e.  through  increased  and  more  collaborative  forest 
management.  Hence,  compared  to  the  previously  mentioned  studies  the 
SIMWOOD operates a more bottom-up approach.  
Sweden and Finland are examples of countries with a large forest resource and 
well-developed  forest-based  sectors,  where  the  wood  mobilisation  is  already 
quite high in comparison to other countries. Germany also has quite high rates 
of  utilisation,  but  the  growing  stock  in  German  forests  is  also  very  high  (as  a 
result  of  a  favorable  climate  and  an  accumulation  of  growing  stock  over 
decades  and  centuries).  Slovenia  also  has  a  high  growing  stock  that  is 
increasing  quickly.  Ireland,  the  Netherlands  and  the  UK  are  examples  of 

June 2020  I  93 

 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

countries  that  have  a  relatively  small  amount  of  forest,  but  where  the  forests 
are growing fast and where the growing stock is increasing. 
The study found that the largest total forest biomass potentials per unit of land 
can  be  found  in  Northern  Europe  (including  the  Baltic  countries),  central 
Europe,  Slovenia,  southwest  France  and  central  parts  of  Portugal.  However, 
these  do  not  represent  additional  potentials:  a  large  part  of  this  potential 
resource is already used to produce materials  and energy and there is limited 
scope  for  further  extraction  of  biomass  in  these  areas.  The  location  of  the 
currently  unused  forest  biomass  potentials  only  partly  correlates  with  regions 
that  currently  have  high  levels  of  wood  production.  This  has  implications  for 
being  able  to  mobilise  and  process  additional  wood  volumes  because  the 
necessary  infrastructure  is  possibly  not  yet  in  place  to  facilitate  mobilisation. 
Quantitatively,  the  SIMWOOD  project  found  that  an  additional  60  Mm3  may 
become available at the European scale compared to today’s levels.27 

Upon  reviewing  these  modelling  studies,  we  can  conclude  that  estimates  vary  widely 
depending  on  the  assumptions  and  boundary  conditions  that  need  to  be  met,  e.g. 
existing policies (LULUCF Regulation), demand for bioenergy, and forest management 
practices: 

▪  Bottom-up studies show that an additional 60 Mm3 may become available compared 

to the 2015 level of harvesting at 420 Mm3. 

▪  Studies that respect the limitations stipulated by the LULUCF Regulation show that 

an additional 0–140 Mm3 can be harvested towards 2050.  

▪  Studies that explore the upper limit of wood mobilisation in EU forests, while not 

letting harvests exceeding the net annual increment, show an additional potential of 
97–235 Mm3 by 2030. 

Forestry Sector Impacts 
Building on the available potential of wood for construction from the EU’s forests, this 
chapter  will  explore  how  much  wood  can  be  made  available  for  the  construction  of 
wooden  frames  and  building  elements,  its  impacts  on  the  forestry  sector  and  how 
much carbon the wood can store. The forestry sector is a relatively complex economic 
sector,  with  various  residue  streams  and  recovered  products  that  need  to  be  taken 
into account in the balance. Figure 22 illustrates the flows of woody biomass and wood 
products for 2015 in the EU.  

SIMWOOD 

27 
https://www.wur.nl/en/project/SIMWOOD-Sustainable-innovative-mobilisation-of-wood.htm  

innovative  mobilisation 

Sustainable 

SIMWOOD: 

(2017), 

of 

wood, 

June 2020  I  94 

 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 56: Sankey diagram of the EU’s woody biomass balance in 2015 (units 
in Mm3).28 

JRC 

28 
https://publications.jrc.ec.europa.eu/repository/bitstream/JRC115777/jrc_sankey_2019_online.pdf 

diagrams 

biomass 

‘Sankey 

(2019), 

woody 

flows 

the 

of 

in 

EU-28’, 

June 2020  I  95 

 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Construction  wood  mainly  relies  on  large  diameter  logs,  meaning  the  sawn 
wood/sawmill subsector. Of the harvested wood entering that sector, around half ends 
up  as  a  residue  going  to  the  pulp  or  panel  industry.  Wood-based  construction  is 
therefore  an  important  driver  for  raw  material  availability  for  pulp  and  paper  and  for 
emerging industries, as sawmilling generates raw materials for these industries (wood 
chips, bark, sawdust, and forest residues). 

Wood Demand vs. Mobilisation Potential 
The  raw  material  impact  of  an  increase  in  wood  construction  can  be  estimated  as 
follows:  A  100%  market  share  of  wood  construction  of  all  building  in  Europe  would 
translate  to  a  maximum  direct  annual  demand  of  around  45–145  million  m3  of  wood 
products, which translates then into around 100-400 million m³ of raw wood, strongly 
depending  on  the  raw  material,  species,  production  technique  and  product  (sawn-
wood needs to be produced from log-wood, while glulam or CLT, OSB, MDF and WIFB 
can also be produces from smaller logs and thinning). 29  

Cross-Laminated Timber 
The main type of wood products used for modern wood construction are CLT, glulam, 
OSB and WFIB. A CLT panel consists of several layers of dried lumber boards stacked 
in alternating directions, bonded with adhesives and pressed to form a solid, straight, 
rectangular panel. An advantage of using CLT is that not only the large diameter logs 
can  be  used,  but  also  thinnings.  Pre-commercial  and  regular  thinning  are  forest 
management activities aimed at maintaining forest health, and the harvested wood is 
generally used for bioenergy purposes. However, using thinnings as a resource for CLT 
production  can  increase  revenue  from  thinnings  and  improve  the  economic  feasibility 
of forest management. 
CLT is typically made from Norway spruce, However, there is growing interest in and 
research  on  use  of  locally  abundant,  under-utilised  timber  resources  for  which  there 
are  no  established  structural  properties  as  feedstocks  for  CLT.  Examples  include  the 
use  of  Sitka  spruce  in  Scotland  and  Ireland;  Italian  marine  pine  in  Sardinia  and 
European beech in Germany and Switzerland.30  

Wooden Buildings as a Carbon Sink 
Wood, on average, weighs 500  kg/m3 and is made up of close to 50% carbon.31 This 
implies that one m3 of wood contains around 250 kg C, or 917 kg CO2. If we assume 
that  wooden  construction  reaches  a  market  volume  of  50  million  Mm3  of  long-lived 
wooden  products  would  be  produced  and  4.6  MtCO2  would  be  locked  into  wooden 
construction  elements  annually.  This  is  a  figure  for  all  of  Europe,  however  there  is  a 
clear  difference  in  market  potential  per  region.  Northern  Europe  has  the  highest 
market potential for additional wood  construction, whereas this is lowest in Southern 
and  Eastern  Europe.  This  potential  is  based  on  local  culture  and  structure  of  the 
construction  sector  and  aligns  well  with  the  relative  amount  of  harvests  foreseen  in 
e.g. the EFSOS study elaborated in the chapter on Wood Harvesting Scenarios. 

 https://www.efi.int/sites/default/files/files/publication-

29  Hurmekoski  (2017),  ‘How  can  wood  construction  reduce  environmental  degradation?’,  European  Forest 
Institute, 
bank/2018/efi_hurmekoski_wood_construction_2017_0.pdf:  The  EU  building  stock  is  renewed  at  a  1% 
annual rate – an area of 240 million m2 is built annually1 . The wood use intensity of wood construction can 
be  assumed  to  vary  from  0.2  m3  /m2  (light  frame)  to  0.6  m3  /m2  (massive  frame).  Thus,  a  simple 
calculation suggests that 100% of the European construction markets could be covered with 45–145 million 
m3  of  wood  products,  translating  to  around  100-400  million  m3  of  raw  wood  (the  conversion  factor  to 
roundwood  equivalent  (RWE)  ranging from 2.0  for  sawnwood  to 2.8 for cross-laminated  timber  (CLT)).  As 
the increment in forests available for wood supply was 769 million m3 in 2010 in EU27 (Eurostat), a 100% 
market  share  of  wood  construction  in  Europe  would  require  a  maximum  of  53%  of  the  annual  growth  of 
European forests. 
30 Rose et al. (2018), Cross-Laminated Secondary Timber: Experimental Testing and Modelling the Effect of 
Defects and Reduced Feedstock Properties, doi:10.3390/su10114118  
31 Wood Ways (2018), Wood and Climate, http://www.wooddays.eu/en/woodclimate/  

June 2020  I  96 

 
 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Table 32: Market potential of wood construction in selected regions in Europe32 

Region 

Market 
potential 
2030 

Countries 

Northern 
Europe 

Central 
Europe 
the UK 

and 

Western 
Europe 

Southern  and 
Eastern 
Europe 

by 

High 

Intermediate 

Low 
intermediate 

to 

Low 

Finland, 
Norway, 
Sweden 

Austria, 
Northern  Italy, 
Southern 
Germany, 
Switzerland, 
The UK 

The 

France, 
Ireland, 
Netherlands, 
Northern 
Germany 

Czech 
Republic, 
Hungary, 
Poland, 
Southern  Italy, 
Spain 

Wood Market Dynamics 
An important nuance in estimating the additional wood mobilisation potential in the EU 
for the construction sector is that over time demand for other end-uses also changes. 
If, for example, the potential is 60 million Mm3
 by 2030, but the demand for biomass 
for  the  pulp  and  panel  industries  increase  by  the  same  amount  this  leads  to  an 
allocation  issue  and  would  likely  lead  to  wood  imports  to  satisfy  demand  for  all  end-
uses. 
The  UNECE  EFSOS  II  study  developed  supply  and  demand  pathways  for  different 
‘worlds’,  characterised  by  different  GDP  growth  rates  and  population  developments. 
One  pathway  (A1)  is  characterised  by  rapid  economic  and  population  growth,  strong 
global  trading  networks  and  a  consumer-oriented  society.  Due  to  rapid  demand 
growth in this pathway, demand surpasses supply by 2020 creating a need for imports 
in  the  order  of  300  Mm3  by  2030.  The  Reference  scenario,  however,  sees  a  slower 
demand  growth  and  efforts  to  increase  local  production  capacity  which  leads  to  an 
overall  balance  in  wood  supply  and  demand  by  2030.  Hence,  developments  in  the 
wood  market  are  sensitive  to  socio-economic  factors  and  depending  on  socio-
economic developments towards 2030, there may be a need to import wood products 
when additional wood mobilisation potential is allocated to the construction sector. 

32  Adapted 
https://www.dissertationesforestales.fi/pdf/article1994.pdf 

from  Hurmekoski 

(2016),  Long-term  outlook 

for  wood  construction 

in  Europe, 

June 2020  I  97 

 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 57: Wood supply and demand in Scenario A1 (EFSOS II study). 

Figure 58: Wood supply and demand in Reference scenario (EFSOS II study). 

June 2020  I  98 

 
 
 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

Figure 59 

Carbon accumulation in trees over lifetime (EFSOS II study). 

June 2020  I  99 

 
 
 
 
 
 
    Impact of Wooden Buildings on Climate, Embodied Energy and GHG-Emissions 

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