June 16, 2022
Graduate School of Frontier Sciences, The University of Tokyo
Musashino University
Sumitomo Realty & Development Co., Ltd.

The University of Tokyo, Musashino University, and Sumitomo Realty Announce the Results ofTheir Research on Decarbonization Through “Shinchiku Sokkurisan” Building Renovation

Improving Building Performance
While Reducing CO2 emissions by 47% Compared to Rebuilding(ton-CO2)

From December 2021 to March 2022, Tsuyoshi Seike, Professor of the Graduate School of Frontier Sciences at
The University of Tokyo, Takayuki Isobe, Lecturer of the Department of Environmental Systems Sciences in theFaculty of Engineering at Musashino University, and Sumitomo Realty & Development Co., Ltd. (President: KojunNishima) carried out the first phase of joint research to establish an environmental evaluation method*1 for therenovations of existing detached houses, with the aim of achieving a decarbonized and the sound material-cycle
society. The results of this research are detailed below.

60.0

Demolition and waste disposal

Foundation, structural materials,
external walls, etc.

Interiors, equipment, etc.

Construction, etc.

50.0

(47％)

40.0
30.0
20.0
10.00.0
建替Rebuilding

BIM (Revit) and 3D modeling (Matterport) were used to create
accurate data models of the material compositions, etc. of existingbuildings for analysis

改修
Renovation

Reusing foundations and structural materials made it possible to reduce
the amount of CO2 emissions from the manufacture of construction
materials by 47%, or approximately 22 t-CO2, per house

This research project performed a building LCA evaluation*2, using digital technologies such as BIM*3 and 3Dmodeling to assess the amount of the building components reused, both before and during renovation of existing
detached houses. The amount of new materials used was also determined based on order statements, etc. The
results of evaluation performed at Sumitomo Realty renovation worksites found that for detached houses inwhich full renovation was performed and significantly improved building performance (earthquake
resistance, thermal insulation performance, etc.), the reuse of foundations, main frames, etc. dramaticallyreduced the amount of new materials used compared to rebuilding the entire building, and cut CO2
emissions by 47%.
Dealing with existing detached houses, which account for a large percentage of Japanese housing stock, will beessential for Japan’s decarbonization. As such, the renovation of detached houses that reuses existing
foundations and structural materials is drawing attention as one effective approach. We will continue this research,with the aim of further advancing decarbonization.
*1: Environmental evaluation method (for renovations) refers to tools and methods for quantitatively and generally assessing the amount of waste generated, newresource usage, CO2 emissions, etc. associated with buildings. By quantifying, it makes possible to visualize reductions, and make comparison with rebuilding,etc. While methods such as the LCA Guidelines for Buildings already exist for newly constructed buildings, such methods have not yet been established forbuilding renovations.
*2: LCA stands for Life Cycle Assessment. LCA is a method of quantitatively evaluating the overall environmental impact of a product across its entire lifecycle.
*3: BIM stands for Building Information Modeling. BIM is a technology to create three-dimensional digital models of buildings by entering and combining material
data, etc.

■ Research methods leveraging digital technologies
In this research, data obtained through 3D modeling using 360°cameras was used to create a digital model using
BIM with a database of structural materials. The movement of materials before and during renovation was thenassessed in detail. As the equipment and material compositions of buildings differ depending on how and when abuilding was constructed, close visual confirmation was performed for areas that could not be determined from thecamera data, which enhanced the accuracy of the system.
The above data confirmed the amount of existing materials used, making it possible to quantify the amount ofwaste generated and new materials used, etc., compared to rebuilding on an empty lot, after demolition andremoval of foundation, and to calculate the corresponding reduction of CO2 emissions.

◆ Research procedure
1. Assess the material composition of an existing detached house before
and during renovation
・ Perform imaging using 360°cameras and carry out 3D modeling・ Visually confirm locations that could not be observed by cameras, such as
behind walls
・Visually confirm waste, and determine the amount of new materials used
Building dollhouse model createdusing 3D modeling

2. Enter the obtained data into the BIM system and perform a detailed analysis
・ Organize information by dimensions and materials for each building material, and enter the data to the BIM
system to create detached house database・ Categorize reused and replaced materials

BIM framework model of an existing building

Creation of a wooden house renovation model and tabulation of individualmaterials using the BIM

3. Enter the data into the LCA tools to calculate the amount of CO2 emissions resulting from the newmaterials used, waste generated, construction, etc. individually・ Detached house data (BIM)・ New material usage data (order statements, etc.)
・ Waste generation data (manifests, etc.)

Input into tools according
to the LCA Guidelines
for Buildings

CO2emissions

■ Background behind the joint research project
In its efforts aimed at achieving carbon neutrality by 2050, the Japanese government has set an interim target of areduction of CO2 emissions from the household sector by 66% by 2030, compared to the FY2013. Achieving thistarget will require immediate action. Although discussions have been carried out on various topics for newly
constructed detached houses, such as improving their environmental performance, little progress has been madetoward promoting energy savings or decarbonization for existing houses, which far outnumber new houses (thereare currently roughly 50 million existing houses).
In 1996, Sumitomo Realty started the housing remodeling business, with its Shinchiku Sokkurisan remodelingbrand. Since then, we have carried out approximately 150,000 “full remodeling” projects to enhance house safetyand livability. In these projects, we have improved earthquake resistance and insulation performance of existinghouses while keeping construction costs down by utilizing existing materials, such as foundations and mainframes. We have also been actively working to promote the decarbonization of existing houses. For example, lastDecember, we have started offering a high thermal insulation remodeling plan to improve the energy-saving
capabilities of houses. In April, we launched SUMIFU × ENEKARI, a service to install solar panels and storage
batteries at zero initial cost in conjunction with our renovation work.
Establishing methods for evaluating the environmental contributions of renovations is a fundamental part ofbuilding systems to promote the decarbonization of existing detached houses. The Graduate School of The
University of Tokyo and Musashino University contacted Sumitomo Realty to request our assistance in theirresearch to create these evaluation methods, due to our broad-ranging construction track record, which covers
from partial to full remodeling. We agreed to give our full cooperation in performing studies at construction sites
and providing data, and the research project began in December 2021.
＜Reference＞“High Thermal Insulation Remodeling Plan by Shinchiku Sokkurisan Launched Nationwide” released on December10, 2021
“Shinchiku Sokkurisan Remodeling Business to Start Offering SUMIFU x ENEKARI, a Solar Power Generation
Service that Delivers Continuous Peace of Mind” released on April 4, 2022
“The University of Tokyo, Musashino University, and Sumitomo Realty “Shinchiku Sokkurisan” Conduct Joint
Research to Establish an Environmental Evaluation Method for Renovations of Existing Homes” released onFebruary 24, 2022 (JP)■ Future research plan
Phase 1

Verify the CO2 emissions reduction effectiveness of existing detached house renovations

Phase 2

Verify the building lifespan extension effectiveness of existing detached house renovations

Phase 3

Verify the adoption of ZEH*1 and achievement of LCCM*2 through existing detached houserenovations

The data obtained from the on-site studies explained above will be organized and used to create a renovation
database. This database will be used to generalize the effect of reduction of waste and new material usage inrenovations of existing detached houses, as well as reduction of the energy consumed in their construction andtransport, etc. In the future, we aim to create an evaluation system that is capable of visualizing (quantifying) CO2emissions reductions with steady degree of precision without performing detailed studies at individual sites.
In order to verify whether CO2 emissions reductions can be expected over the long term, not only at the time ofrenovation, Phase 2 of the research project will verify the effectiveness of renovation in extending the useful livesof existing detached houses, while Phase 3 will verify the effectiveness of introducing energy saving and energy
creation equipment in existing detached house renovation. Through these studies, we aim to establish anenvironmental evaluation method (for renovations) for existing detached houses, that enables a comparison ofrebuilding and full renovation with building LCA evaluation over an extremely long period, from building
construction to eventual demolition.
This environmental evaluation method has the potential to be used in effective decarbonization approaches forexisting detached houses, which account for a large percentage of housing stock, and can further advance themovement to reuse existing detached houses.
*1: ZEH refers to Zero Energy House. Houses with net zero annual primary energy consumption due to energy saving and energy creation.
*2: LCCM refers to Life Cycle Carbon Minus. Houses with negative CO2 emissions over the course of their entire lifecycle, due to CO2 emissions reduction efforts
during the construction, usage, and disposal stages, together with the generation of renewable energy.

■ Joint researchers
Tsuyoshi Seike – Professor, Graduate School of Frontier Sciences at The University of Tokyo
Tsuyoshi Seike graduated from the Department of Architecture in the Facultyof Engineering at The University of Tokyo in 1987. He worked as a Research
Associate in the Department of Architecture before joining the GraduateSchool of Frontier Sciences in 1999.
He engages in research in renovation/demolition technologies, recyclingtechnologies, and environmental evaluation systems, from the viewpoints ofbuilding production and the environment.
He is the development leader for CASBEE for Detached Houses, andplays a central role in creating health checklists and resilient housechecklists.
His publications include Sustainable Housing (editorial supervisor and cowriter), Creating Facades (co-writer), and Rethinking Living Environments From Smart to Healthy (co-writer).

Takayuki Isobe – Lecturer, Department of Environmental Systems Sciences in the Faculty ofEngineering at Musashino University
Takayuki Isobe received his Doctorate from the Graduate School of Frontier
Sciences at The University of Tokyo in 2015. In 2016, he was appointed tothe Department of Environmental Systems Sciences in the Faculty ofEngineering at Musashino University.
His research has focused primarily on environmental evaluation systems
that relate to the recycling of construction materials and building lifecycle(construction, usage, and disposal) environments.
He is the Director of the LCA Subcommittee of the Research Committee
on Global Environment in the Architectural Institute of Japan.

Sumitomo Realty & Development Co., Ltd.
Sumitomo Realty has been working to solve social issues through its
business activities under its fundamental mission to “Create evenbetter social assets for the next generation.”
Going forward, the Company will further contribute to realizing asustainable society by creating high-value social assets withenvironment and social awareness.
＜Our Initiatives on ESG and SDGs＞
https://www.sumitomo-rd.co.jp/english/sustainability/
The initiatives related to this release contribute to the following SDGs objectives:
Goal 3: Good health and well-being
Goal 7: Affordable and clean energy
Goal 9: Industry, innovation and infrastructure
Goal 11: Sustainable cities and communities
Goal 12: Responsible consumption and production
Goal 13: Climate action
Goal 15: Life on land

＜Reference＞“Shinchiku Sokkurisan” Remodeling by Sumitomo Realty
The Shinchiku Sokkurisan remodeling business was launchedafter the Great Hanshin Awaji Earthquake of 1995 with thedesire to renovate existing houses to make them earthquake
resistant without the high cost of rebuilding. Based on ourconcept of safe and secure housing, it boasts the industry’s
foremost track record for full remodeling featuring earthquake
reinforcement work and a clear fixed-price system.
It marked 25th anniversary this year, since its launch in 1996, and the cumulative total of units
contracted exceeded 150,000 units (as of June 30, 2021). Today, the Shinchiku Sokkurisan has become so
popular across the nation that it is a brand synonymous with full remodeling. By leaving main structuralcomponents intact and improving housing functionality without rebuilding, the Shinchiku Sokkurisan
remodeling contributes to not only extending the useful lives of existing houses, but also to addressing thesocial issues concerning houses in Japan by being environmentally friendly, i.e. minimizing industrial
waste, CO₂ emissions, and waste of resources.

Unique Features of “Shinchiku Sokkurisan” Remodeling

BeforeInterior stripped down to
its main frame

After(1) Clear fixed-price system with no additional charge* (developed by the Company)
There will be no additional charges in the event that an unforeseen situation arises after construction has
begun, such as discovering a rotten pillar that needs to be replaced after a wall is torn down.
This relieves customers’ concerns about costs, which is often the case with remodeling work, and allows
them to leave the work to us with peace of mind.
*Only when there are no changes to the scope of work requested by the customer.

(2) A dedicated sales engineer with knowledge and proposal skills manages the entire project
From initial consultation to planning, estimating, and construction management,a dedicated sales engineer manages the entire project. This prevents problems,such as the customer’s requests not being clearly communicated to the constructor
and not being reflected in the construction work, and allows us to proceed with theconstruction of the house based on the customer’s requests.
(3) A lineup of reliable seismic resistance and vibration control reinforcements for buildings of allages
For earthquake countermeasures to ensure the safety of buildings, we haveestablished a system that can propose the most suitable seismic resistanceand vibration control reinforcement plan for buildings of all ages. Our plans
combine seismic reinforcement proven through our experience in construction
and vibration control reinforcement, which includes a new patented method.
(4) Reliable quality through dedicated master carpenters, extensive construction manuals, etc.
We achieve reliable construction quality through the mastery of our dedicated master carpenters whoare skilled in large-scale remodeling, as well as detailed construction manuals based on data
accumulated over many years and a thorough inspection system.
(5) Reliable support system (after-sales service)
As for our regular after-sales service, we visit our clients for inspection one month,three months, and one year after completion. In addition, our Customer Center
always responds to inquiries about problems and repairs regardless of the urgencyof the situation.

＜Reference＞“Shinchiku Sokkurisan”– Model of extending useful life of existing houses by renovation
Key issues with the housing stock• Shorter life cycle than houses in
Europe and the U.S.

Extended useful life through improved functionality
Earthquake-proofing and seismic retrofitting
Revised floor plans to suit changing lifestyles

Disaster People
Prevention• Insufficient earthquake
resistance and insulation• Mismatches between lifestyles andfloor plans

Through the Shinchiku
Sokkurisan
remodeling:• Environmental impact fromwaste generated whenrebuilding

Reduced environmental impact
Reduced waste by leaving main structural components
intact to lower CO2 emissions and improve energy-saving
functionality
Renovation of traditional-style houses harmonizes
the cityscape
Traditional-style house exteriors left in place, harmonizing
with other homes in the community; interiors modernized
to match current lifestyles

EnvironmentCommunity■ Social issues concerning houses in Japan
Although the penetration rate of earthquake resistant houses in Japan is increasing every year, there are still many houses with low
earthquake resistance. Moreover, the lives of houses in Japan are relatively short compared with those in Europe and U.S. and the shortrebuilding cycle has emerged as an issue in contemporary Japan. Waste from the demolition of houses accounts for a large share of waste
discharged by the construction industry. It is called for that lives of houses should be extended to facilitate the shift to a stock-type society
where houses could be used by successive generations.
❶ Earthquake-resistance of housing stock*Approx.

Without earthquake
resistance
7 million units*
With earthquake
resistance
6.1 million units*1981 or earlier➋ International comparison of the average ➌ Breakdown of construction waste
age of houses
Repair 570(Years)

100

80.680From 1982
onwardFrom 1982 onward
With earthquake
resistance
40.5 million units*

66.6

House: 7,750(51% of thedischarged waste
through demolition)

60
40

38.2

200

JapanUSDemolition

UK

Building Work/
Renovation
Private Sector
Civil Engineering(Unit: thousand tons)

15,120Total:

12,95072,700 40,540 Public Sector

Civil Engineering

3,520

Sources: ❶ Ministry of Land, Infrastructure, Transport and Tourism“Progress of Earthquake Proofing of Houses”➋ Ministry of Land, Infrastructure, Transport and Tourism“International Comparison of Average Age of Houses Deregistered in 2018”➌ Ministry of Land, Infrastructure, Transport and Tourism “Residential Land Session, Panel on Infrastructure Development (36th) ”■ Shinchiku Sokkurisan initiatives concerning social issues
Extending the useful lives of houses through seismic reinforcement
Shinchiku Sokkurisan offers proposals for improving the house’s functionality to make it earthquake
resistant without rebuilding mainly through seismic reinforcement work based on earthquake
resistance diagnosis that meets the government’s safety standards.
Moreover, in the Kumamoto Earthquake of 2016, a series of powerful tremors caused the collapseof houses previously considered not to need seismic reinforcement under current laws. In view ofsuch circumstances, we developed a proprietary method to counter such a series of powerfultremors. With the addition of this new method, we now offer seismic reinforcement and damping
plans suitable for houses of all ages.
We are promoting houses where people can continue to live in with peace of mind byimproving the safety functions through this reinforcement work.

Contributing to the reduction of the environmental impact
Shinchiku Sokkurisan remodeling contributes to the reduction of theenvironmental burden by extending the life of the house through earthquake
reinforcement while the principal structural elements of the house are retained,
thus minimizing industrial waste discharge, CO2 emission, and waste ofresources, compared to the demolition involved in building a new house.

Revised floor plans to suit changing lifestyles
In addition to seismic reinforcement, Shinchiku Sokkurisan offers remodeling thatmakes living comfortable, with thermal insulation, waterproofing, barrier-freedesign, etc. Furthermore, in response to changes in family structures and aging
population, we offer solutions customized for the lifestyles without rebuilding,such as layout changes, extensions, downsizing, transformation of a two-story
house to a one-story house, or a two-family house.

Solution for rapidly
increasing disused houses
The high number of disused
detached houses has becomea social issue in Japan.
Through remodeling, turningthem into social welfare
centers, share- houses,
travelers’ inns, etc., wecontribute to utilization ofexisting house stocks andsupport safe and sustainablecity.

Interior stripped down to
its main frame
AfterBefore