Research Trends and Results

Development of “simplified block performance
evaluation system for densely built-up areas”
KATSUMATA Wataru (Dr. of Engineering) , Senior Researcher
Urban Development Division, Urban Planning Department
IWAMI Tatsuya , Senior Researcher
Construction Economics Division, Research Center for Land and Construction Management
MIKI Yasuhiro (Dr. of Engineering) , Senior Researcher
Residential Environment Planning Division, Housing Department
NISHIZAWA Shigeki (Dr. of Engineering) , Senior Researcher
Environment and Equipment Standards Division, Building Department(Keywords) Densely built-up areas, Group provisions of Building Standard Law, Harmonious rebuilding rule, Fireprevention / Evacuation, Sunlight / Daylight, Ventilation / Airflow
1. Forward
In order to improve disaster prevention performance andliving environment within blocks of densely built-up areas
where group provisions of Building Standard Law(obligation for a building site to adjoin the road, road slant
plane restrictions, allowable building coverage ratiorestrictions, etc.) are strictly enforced, it is consideredeffective to utilize “special methods for harmonious
rebuilding”, such as combinations of building design
systems and street scenery-improving district planning. 1)
These methods, with permission and authorization of thedesignated administrative agency to replace general building
regulations with a local rule to equivalent standard in termsof performance, promote individual rebuilding at each site
within a district. These methods are clearly expressed as abasic policy for promoting development and improvement in
the densely built-up areas in “Basic Plan for Housing(National Plan)”. 2)
2. Simplified block performance evaluation system fordensely built-up areas
To promote utilization of special methods for harmoniousrebuilding, it is important for the administrator andcommunity planning consultant to evaluate the actual
harmonious rebuilding rule plan during the consensus
formation between the landowners and leaseholders.
Specifically, evaluations regarding the ability to secure thesame level of block performance (fire safety and residentialenvironment performance) as the general regulation, theimprovement level from status quo, in comparison withalternative plans and so forth.
Therefore, National Institute for Land and InfrastructureManagement is developing some PC software called“simplified block performance evaluation system for denselybuilt-up areas”(fig.) The system, by entering 3 dimensional

data of such as building, road and site, which is current status
and after rebuilding in accordance with harmonious
rebuilding rules, and local conditions such as latitude andwind, allows a user to easily evaluate block performance inthe area of fire prevention, evacuation, sunlight, daylight,ventilation and airflow.

Fig. Image of simplified block performance evaluation
system for densely built-up areas
3. Future issues
In parallel to the system development, Housing Bureau,
academic experts and local municipalities are working

Research Trends and Results
together to examine the target level for block performance tobe secured in densely built-up areas. By the end of fiscal year
2013, we plan to publish the “guideline on making
harmonious rules for rebuilding” with the system, to be fully
available at the sites. 3)【Reference】
1）Guidebook on Special Permissions in the Zoning Codeunder the Building Standard Law to Promote Rebuilding inDensely Built-up Areas” by TECHNICAL NOTE ofNILIM (2007)
http://www.nilim.go.jp/lab/bcg/siryou/tnn/tnn0368.htm
2)“Basic Plan (National Plan) for living” by Ministry ofLand, Infrastructure, Transport and Tourism(2011)
http://www.mlit.go.jp/jutakukentiku/house/torikumi/jyuseik
atsu/hyodai.html
3)Development of supporting technology onmaking
harmonious rules for rebuilding in densely built-up
areas(NILIM Urban Development Div. HP)
http://www.nilim.go.jp/lab/jeg/index.htm