ENERGY CONSUMPTION THROUGH TIMBER TRANSPORTATION AND THE WOODMILESTHE POSSIBILITIES OF THE WOODMILES INDEXES FOR EVALUTAION OF BUIELDING

1
Takashi FUJIWARA Ph.D
Hideshi NODA Ph.D 2
Takuya SHIMASE 2
Satoshi TACHIBANA Ph.D 32
Takuya TAKAHASHI Ph.D
1

Japan Federeation of Wood Industry Associations, 6F Nagatacho BLDG. 2-4-3 Nagatacho Chiyodaku,
Tokyo, 100-0014, Japan, fujiwara@t.nifty.jp
Forestry and Forest Products Research Institute3
The University of Shiga Prefecture
2

Keywords: woodmiles, woodmileage, CO2, discharge, transportation, energy, consumption, timber,

Summary
About one third of constructions in Japan have wooden structure, and timber is considered to be one of theimportant building materials. One of the features of timber as building materials is that very little amount ofenergy is consumed under its production processes. However it is pointed out that the energy consumption
during transportation processes of timber from forests over seas to Japanese market is quite larger than theenergy consumption during its production processes.
In order to shorten the transportation distance of the timber used for construction, and to promote a demand
for locally produced timber, the Woodmiles Forum was launched in June, 2003. The forum is aiming at thedevelopment and promotion of the woodmiles indexes, including “the woodmileage for building” which
represents a sum of the products between the volumes of wooden materials of a house multiplied by thecorresponding actual transportation and “the woodmileage CO2 for building” showing the quantity of carbon
dioxide discharged in transportation processes.
This paper clarifies the possibility of the woodmiles indexes as a tool to evaluate environmental load intransportation processes of timber materials, through several evaluation case studies.

1.

Introduction

In order to evaluate environmental load of buildings, sophisticated methods including various kinds of life
cycle assessments are being developed. Up until now it cannot be said that methods developed have spreadenough or that there has been enough reward from massive amounts of efforts. One reason as pointed out
is the difficulty for users of such methods to interpret results from an evaluation despite methods such as
LCA aiming to be quite comprehensive.
The woodmiles indexes, to be dealt in this paper, were developed by the Woodmiles Forum in Japan toevaluate some aspects of the environmental load of building materials. It may be limited because theseindexes have a restricted range of timber transport distances if considering this index in regards toevaluations of the environmental loads from buildings. However, it could give us an opportunity for
propagation, because
1) this index provides its users with a simple and clear index of environmental load and2) this index provides a measurement for forming a network of supply of building materials.
In this paper we will explain the background the method of evaluation with the woodmiles indexes, and thepossibilities and the assignment of them.

2.

Timber Building Materials in Japan and its Sources of Supply

2.1

Timber as Building Material in Japan and its Evaluation of Energy Consumption

In Japan, 173 million m2 of buildings were built in 2003, 63 million m2 of them were wooden frame buildings.
Timber itself is one of the most important building materials in Japan.

It is pointed out that one of the features of timber as a building material is its efficiency of energy
consumption in production processes. Nakajima, S. and Okuma, M. reported that the quantity of carbon
emitted from the production of one cubic meter of timber is fur smaller than that of other construction
materials. (Table 1)
Table1 Energy Consumption and CO2 Discharge in Production Process of Construction Materials
Fossil energy

CO2-discharge

consumedMaterial

MJ/m3

MJ/kg

kg/m3

kg/t

Sawn timber air dried

1.5

750

110

55

Sawn timber kiln dried

2.8

1390

205

103

Plywood

12

6000

799

440

Particle board

20

10000

1129

733

Steel

35

266000

2567

19507

Aluminum

435

1100000

31900

80667

Concrete

2

4800

183

440

Nakajima, S. and Okuma, M. 1991

2.2

Sources of Supply of Timber Used in Japan and the Environmental Load from Timber
Transportation

In 2002, the demand for timber (sawn timber) for Japan was 34,856 thousand cubic meters (log equivalentbasis). 70% was used as building materials. As to the sources of supply, domestic timber accounts for 32%
of the supply and the others are supplied form foreign resources.. Main sources of imported timber of Japan
are North America, South East Asia, Russia(Asian), Europe and New Zealand.
The Table 2 shows results of calculations that average the quantity of carbon dioxide discharged fromdistances of their transportation and its process of transportation, after analyzing routes of transportations oftimbers from its origin.
Table 2 Distance and CO2 Discharged of Transportation of Imported Sawn Timber
Distance of Transportation (km)OriginTotal

Sawn Product
boat

truck

CO2
discharge

Raw Log
rail

boat

truck

(kg/m3)

rail

North America

8064

7710

254

0

0

100

0

160

South East Asia

5490

5736

254

0

0

0

0

131

Russia

6145

1921

254

3800

0

170

0

156

Europe

23274

22570

254

350

0

100

0

326

New Zealand

9770

9116

554

0

0

100

0

231

Fujiwara, T. and the Woodmiles Forum, 2005
Timber from Europe, the farthest major origins from Japan, travels 23 thousand kilometres. 326 kilograms ofcarbon dioxide per one cubic meter of timber is discharged from its transporting process. Fig.1 shows acomparison of this figure with the quantity of carbon dioxide discharged from the production processdescribed in Table 1. It is clear that transportation of timber through long distances has more environmentalload than the production process of the timber has.

kg-CO2 /m3

231
160

131

156
103
55

Tr

an

sp

fr o rt ao
fr m it oom N n̲o
So r th ̲ ̲̲̲̲u t A ̲̲̲he me ̲ea r ic
fr s t aom Asfr fr o R u i aom sPr m N E siaoe u
Sa ce w r op
w ss Z e e
Sa n lu i n g al awn m ̲̲̲ ̲ n dblu e r ̲̲̲ ̲m̲b e ai r ̲ ̲̲dr
k i rie
ln
d
dr
ie
d

Source:The Woodmiles
Forum(2004)

326

350
300
250
200
150
100
50
0

Figure 1 CO2 discharged on timber transportation to the Japanese market and timber production process(Source: Fujiwara, T. and the Woodmiles Forum 2005)

2.3

Comparison of Timber Transportation Distances by Importing Countries

Further, Fujiwara, T. compared the transportation distances of timbers in importing processes for three
countries Japan, U.S.A. and Germany, using the statistics of trading 2000 by the Food and Agriculture
Organization. The U.S.A. imported the largest quantity of timber in the world and Germany imported largest
quantity of timber in Europe. The Table 3 shows respective quantities of imported timber for each country by
distances from the origins.
Table 3 Timber Importation Volume of Major Importing Countries by Distance form Origin
thousand cubic meters
Distancefrom origin
Total import of timber

Japan

USA

Germany

52009

100.0%

60357

100.0%

22790

100.0%

0

0.0%

55889

92.6%

9378

41.1%

1000-8000km

33393

64.2%

2845

4.7%

13074

57.4%

8000km-

18616

35.8%

1623

2.7%

338

1.5%

-1000kmFujiwara, T. 2002
If the distance of transportation is divided into three categories, U.S.A., which imported 93% from Canada
depends the most imported timber on the nearest sources. Although U.S.A. has imported valuable timbersuch as Mahogany and Teak from South-East Asian countries more than 10,000 kilometres away, it only
comprises 3% of the total amount of timber imported. On the other hand, Japan is one of the few countries
that import substantial amount of timber from countries more than 10,000 kilometres away. If we introduce a
concept of “Woodmileage” (total transporting distance that multiplies imported quantity of timbers andtransporting distances), though the quantity of imported timbers for Japan would be less than that for U.S.A.,
the woodmileage for Japan would be more than 4 times as much as that of U.S.A. (Fig. 2)

400

３８４

300
200
100

８４
５２

１８
６０

１２

0
Japan

Figure 2

USA

Importaion Volume:
million m3
Woodmileage:
billion km m3

Germany

Comparison of woodmileage of imported timber in major timber importing countries.

3.

Development of the Woodmiles Index

3.1

The Woodmiles ForumAs described above, the energy consumed for the transportation process of timber is a critical factor inenvironmental loads and it is especially an important problem to Japanese consumers. As this problem wasbrought to their attention the Woodmiles Forum ( here in after refereed as “the Forum”) was founded in June,
2003.
The purpose of the Forum is the development and promotion of the woodmiles indexes in order to shortentransportation distances of timber used for building houses and to revitalize local timber consumption. The
Forum's goal is to contribute to realize the sustainable society by promoting the use of local resources inJapan.

3.2

The Woodmiles Index for Building and its Structure

To achieve the above mentioned objectives the Forum developed a manual to provide a reproducible andobjective method of calculating the "Woodmiles Indexes for Building".
The manual revised in March 2005 defines the following four indexes for evaluation of building construction.
Building Woodmileage(BWM)
Actual distance covered in transporting timber of the applicable type used in the construction of a building(hereafter, applicable timber materials) from each place of harvest (timber type-specific woodmiles)
multiplied by the respective volumes of timber transported from each place of harvest (unit: km m3)
Building Woodmileage CO2 (BWMCO2)CO2 emissions equivalent to the energy expended in covering the above distances according to the types oftransportation used (road, rail, sea, etc.) for each form of timber (unprocessed or processed) (unit: kg- CO2)
Building Woodmileage L (L = linear)(BWML)
The linear distance from each place of harvest (timber type-specific woodmiles L) of applicable timbermaterials to the construction site, multiplied by the respective volumes of timber transported from each placeof harvest (unit: km m3)
Logistics Stops Knowledge Level(LSNL)
The degree, expressed as a proportion of total woodmileage, of applicable timber materials for whichknowledge of processing and storage stops on the way from each place of harvest to construction siteenables the calculation of an accurate woodmileage figure

3.3

Practical Meaning of the Woodmiles Index: Case Studies of the Large Scale Wooden Frame
Domes

3.3.1 Large Scale Wooden Frame Domes as Objects Used in Evaluation Studies
The building of large scale wooden frame domes has been increasing in Japan in recent years. They playrole of symbol of promoting (local) timber utilization in each areas. We chose the largest three domes of thedomes built since 1990 and compared the woodmiles indexes calculated from structural timbers used inthese buildings. The building descriptions are shown in the Table 4.

Table 4 Building Description of the Dome
Name

Izumo Dome

Odate Jyukai Dome

Location

Izumo City,
PrefectureTime ofbuilding

Oct.1990 to Mar.1992

Jul. 1995 to Jun. 1997

Dec.2002 to Mar.2004

Building
Areas

16,277 m2

21,911 m2

10,966 m2

Height

49m

52m

38m

Structure

Arch of glued laminatedtimber of Douglas fir

Arch of glued laminatedtimberofJapanesecedarArch of glued laminatedtimberofJapanesecedar

Timbers
used forbuildings

2150 m3

4273m31381 m3

Type oftimberOrigin ofTimberShimane

Odate
City,
Prefecture

Akita

Konohana Dome

Douglas fir

Sugi

Sugi

(Pseudotsuga menziesii)(Cryptomeria japonica)(Cryptomeria japonica)

North America

Akita Prefecture, Japan

MiyazakiJapan

Izumo Dome

Odate Jyukai Dome
Odate Jukai Dome, Akita Pref.
1997

Izumo Dome
Shimane Pref.
1992

Figure 3

MiyazakiCity,
Miyazaki Prefecture

Prefecture,

Konohana Dome

Konohana Dome
Miyazaki Pref.
2004

Large Scale Wooden Frame Domes in Japan ( Photos are provided by the City Hall of Izumo City
Takenaka Corporation/ Miyazaki Wood Techno Co.,Ltd.)

3.3.2 Supply Process of timber and Outlines of the Woodmiles Indexes
All of these domes are large arch shaped structures comprised of glued laminated timbers used as the main
structural material. Although the Izumo Dome which was built at an earlier stage used north American
Douglas fir (Pseudotsuga menziesii) for its structural material, the other two domes that were built at the
production centers for Japanese cedars (Cryptomeria japonica) in later stages used Japanese cedar
supplied from their own prefectures.
Transportation and production processes of the timber used for the Dome are described in the Table 5.

Table 5 Production and Transportation Process of Timber Used for the Domes
Izumo Dome*1

Odate Jyuaki Dome*2

Konohana Dome*3

Yoneshiro Riv. Basin

Mimikawa Riv. Basin

Akita Pref.

Miyazaki Pref. *440km by truck

Harvest site

Bend, OR.

Transportation

236km by truck

30km by truck

Saw mill

Springfield, OR.

Yonesiro Riv, Basin

Transportation-

50km by truck

Dry kilnditto

Ttransportation

32km by truck

710km bytruck

52km bytruck-

Laminating mill

Cottage Grove, OR.

Wada
Village
NaganoPref.

Odate City

ditto

Transportation

205km by truck

Export port

Portland, OR.

Transportation

8543km by boat

741km bytruck

7km bytruck

93km by truck

Import port

Kobe, Hyogo Pref.

Transportation

308km by truck

Building site

Izumo, Shimane Pref.

Total distance

9272kmCO2discharge
per unit

246kg/ m3 *5

ditto

Akita Pref.

Odate, Akita Pref.

Miyazaki, Miyazaki Pref.

1531km

138km

3

3

28kg/m *5

162 kg/m3
2356 m3

Miyazaki Pref.
-

Kazuno City

286kg/m *5

Togo Town

2175 m3

133km
27km/ m3 *5

Timber Vol.

2150 m3

Woodmileage

19934 ‘000km m3

3685 ‘000km m3

453 ‘000km m3

WMCO2

529ton718ton37ton*6

WMCO2 (sim.1)*7

529ton1052ton

340tonWMCO2 (sim.2)*8

58ton

116ton37ton

4273 m3

1381 m3*1 Source: Tanaka, S. Japan Lumber Importers’ Association/ Watanabe, T. Government of Shimane Pref.
*2 Source: Shimizu, K. Government of Akita Prefecture*3 Source: Jodo, H. and Hidaka, K: Government of Miyazaki Prefecture*4 Some part of timber is from the other area in the same prefecture but most(85%) of total timber is from the
Mimikawa River Basin*5 The CO2 emission units used to calculate woodmileageCO2 are 0.18515kg-CO2/km m3 for truck and0.01095kg-CO2/km m3 for boat. (The Woodmiles Forum “Manual for Calculation of Woodmiles Indexes for
Building Version 2005”)*6 The figure includes that of the timber come from the other area than the Mimikawa River Basin.
*7 The figure calculated under the condition if the timber had been transported from oversea as the same
condition as that of the Izumo Dome
*8 The figure calculated under the condition if the timber had been transported from local area the same
condition as that of the Konohana DomeFor the Izumo Dome constructed in 1992, Douglas fir timber was harvested in the Cascade Mountains near
Bent, Oregon. Logs are transported to a saw mill in Springfield OR. Processed and dried laminar wastransported to a glued laminated timber factory located in Cottage Grove, OR. Possessed timber (Glulam)was transported via Portland OR. and Kobe, Hyogo Pref. to the construction site in Izumo City, Shimane Pref.
For the Odate Jyukai Dome constructed in 1997, Japanese cedar timber was harvested in the National
Forest under the Akita Regional Forest Office, sawed in local sawmills and kiln dried in Kazuno City, Akita
Pref. Originally, the timber was planned to be assembled into glued laminated timber at a newly constructedfactory in Odate, Akita Pref., but because of restrict time schedule timber used in the early stages of thebuilding was transported to Wada Village, Nagano Pref. 700km away, where an operational large scalelaminated timber factory was running, and transported again to Odate City where a construction site was
located. The other half of the timber was processed into glued laminated timber in the newly constructedfactory in Odate City near the construction site.
For the Konohana Dome constructed in 2004, Japanese cedar timber was harvested in forests located in the
Mimikawa River Basin, the north of Miyazaki Pref. and sawed dried and assembled into glued laminatedtimber at factories located in the same area. The possessed glued laminated timber was transported to theconstruction site in Miyazaki City, about 100km south of the factories.
These descriptions of timber supplying processes to the building project of big domes constructed at
different time shows that, as the time goes on, timber supplying processes to large scale wooden framed
dome in Japan had changed. Owing to the progress of infrastructure of supplying heavy timber for large
scale construction in Japan, both the harvest location and the processed site had been getting nearer to theconstruction site. This kind of discussion shows the possibility of woodmiles study to analyze social aspect of
circumstances around construction.
The result of calculation of woodmiles indexes are shown in table 5 summarized as follows.
1) As to the woodmileage, the figure of the Izumo Dome whose timber was transported from North America
was the largest, followed by that of the Odate Jyukai Dome and the Konohana Dome in order.
2) As to woodmileageCO2, the figure of the Odate Jyukai Dome whose timber had the largest volume andwas traveled more than 1400 km in Japan by truck was the largest, followed by the figures of the Izumo
Dome and the Konohana dome in order.
3) When compare unit WMCO2 per m3, the numbers line as the Izumo Dome> the Odate Jyukai Dome> theKonohana Dome. We can make simulation of construction of all domes with the same timber used in the
Izumo Dome or the Konohana Dome. The result is listed in the Table 5 and outlined in the Figure 4.

Unit:ton
1200

1052

1000
800

CO2 discharged in
reaaltransport
process

718
529 529600

340

In case imported
materials had been
used.

Kinohana DomeIn
case
locally
harvested
andprocessed materials
had been used.

400
200

58

116

37 37

0
Izumo Dome
Figure 4

Odate Jyukai DomeResult of an estimate of the building woodmileage CO2 from the construction of the three biggest
wooden frame domes in Japan

Figure 4 shows quantities of the building woodmileageCO2, comparing those calculated if these building had
been constructed with locally harvested and processed timber like the Konohana Dome and imported timber
like the Izumo Dome .
A solid line shows an estimate of CO2 in the real transport process, a broken line(right) shows the result froma simulation of the timber that had been imported, and a broken line (left) shows that of the timber that had
been harvested and processed locally.

In case of the Odate Jyukai dome, for instance, a discharge of about 1000 tons of carbon dioxide had been
cut down as the neighboring Japanese cedars were used for its building when compare with a case if it had
been built with imported timber.
The forest absorbs the carbon dioxide in the air absorbing it into the wood. 1000 tons of carbon dioxide isequal to the same amount of carbon dioxide a forest the size of Odate Jyukai absorbs for more than 20
years.

4.

Conclusion: the Possibilities and the Assignments of the Woodmiles

In the above sections we explained background of woodmiles, and processed and result of calculating
woodmiles indexes. The case study of evaluation of energy consumption of timber transportation for thelarge wooden frame domes in Japan with woodmiles indexes shows that both processes and the result ofwoodmiles provide us with the following information.
1) The way of supplying timber for construction affect a lot for energy consumption through transportation
processes.
2) Both location of harvest and processed site are important parameters affecting energy consumption
through transportation.
3) Not only transportation distances but their measures (by truck, train or boat) are important factors forwoodmiles indexes.
4) As large scale wooden frame constructions are expected to play role of symbol to promote local timber,
evaluation of environmental load of these constructions with woodmiles indexes provides clear indicatorto support local timber utilization.
Through these processes to evaluate woodmiles indexes, other than above mentioned energy issue, social
aspect surrounding construction of buildings are also assessed. In recent years, capacity of heavy timber
supply in Japan to construction of large scale buildings has greatly increased, and it would help improveenergy efficient construction activities. This kind of discussion can be another possibility of study of thewoodmiles indexes.
The following themes remain for further studies.
1) Further elaboration on a unit of transportation energy that indicates the relation between the transportation
distances and the environmental loads are needed.
2) In order to increase numbers of case studies, it is necessary to develop more sophisticated and simple
procedures and user-friendly tool to calculate woodmiles indexes.
3) It is necessary to develop sophisticated way of present implications of the figures of woodmiles indexes tobe understood commonly.
4) The possibilities of contribution of woodmiles to more comprehensive method of evaluation ofenvironmental load like LCA remains for a topic on future discussions
In Japan, green purchasing activities have been raised in both public and private sectors, recently. It would
be getting more important to provide the consumers with reliable information related to the processes of
production and transportation of each commodity. The concept of woodmiles would be one of the key words
to evaluate the environmental load for building and transparency of the link between the consumers and theforests.

References
Nakajima, S. and Okuma, M., 1991, Promotion of Wood Utilization for Mitigation of Global Warming, Wood
Industry, Vol. 46, in Japanese
Fujiwara, T. 2002, Woodmiles and house constructed with local timber, Wood Information, Oct. 2002, Japan
Wood Information Center in Japanese
The Woodmiles Forum, 2003, The Goal and Purpose of the Forum” http://woodmiles.net/gaiyou.htm inJapanese
The Woodmiles Forum, 2005, Manual for Calculation of Woodmiles Indexes for Building, Version 2005
Fujiwara, T. and the Woodmiles Forum, 2005, Average transportation distance and environmental load fromthem for ordinary distributing sawn timber in Japan, the Woodmiles study note #5, in Japanese