Messages from Departments and Centers of NILIM

Reform Promotion of Existing Housing for Formationof High Quality Housing StockMIZUTANI Akio, DirectorHousing Department(Key words)

Stock type society, long term high quality housing, circulation of existing housing, market of housing

renovation

1. Introduction
The housing stock of Japan is considered to be about
57,600,000 (2008) units. Of this, the number of newresidential housing units per annum is about 800,000(2012). In addition, the average life until demolition isshort compared with other countries being more or less
30 years. Slated for the formation of high quality housing
stock, the transformation from a housing market
centering on new housing to a stock type housing market
where high quality housing is cyclically utilized acrossgenerations, or in other words, as well as supplying
quality new houses, accelerate the formation of highquality housing stock by reforming existing houses andrealizing a society where things are used for a long periodof time, to “produce a good thing, improve it and use it
carefully over a long time” is assigned in order to realize
the transfer to a new environment.
The four targets upheld in the Housing Life Basic Plan
(revised in 2011), which is provided based on theHousing Life Basic Act (2008) indicate appropriate
management and renewal for housing, and environmental
improvement for the housing market where appropriately
realizing a variety of residential needs, as well as
development policies, of environmental improvement topromote appropriate maintenance and reform, theformation of high quality stock to be utilized for thefuture are described to carry out the development ofpolicies.
2. For a society utilizing high quality housing longterm
Using housing for a long duration of time restricts
elimination of wastes in parallel with demolition andremoval of housing, as well as decreasing the load onenvironment, reducing the burden of housing due to thereduction of expenses for replacement building, and links
to shifting to more a affluent and more tendered

livelihood.
For this realization, based on the Act on the Accelerationof Dissemination for Long High Term Quality Housing(2009), dissemination of long term quality housing
contributing to the formation of quality housing stock has
been promoted, and in respect to new residentialbuildings, quality housing supply by the long term highquality housing certification system currently is being
carried out.
In the future, the shift to high quality stock durable forlong term uses is a crucial subject for existing housing, it
is required to promote efforts for the improvement ofexisting stock, as well as an increase in the capability of
new residential housing.
In the total reform plan illustrated in the chart, support forreform and dissemination for long term quality housing
for the promotion of the enhancement of existing housing
stock shall be projected, as well as environmental
improvement for reform market and existing housing
distribution.
3. Efforts up until now
For the formation of quality housing stock by the reformof existing housing, we will carry out deliberations from avariety of viewpoints such as earthquake resistance,energy conservation, barrier-free construction or the like,and necessary reforms shall be carried out for quality
housing capable of realizing comfortable long term
inhabitation.
As aforementioned, although the formation of quality
housing stock capable of being used for a long durationof years is being carried out through long term quality
housing authorization, the following eight items are theevaluation items indicated in its authorization standards:
degradation countermeasures, earthquake resistance,
maintenance and management / easiness of renewal,
variability, barrier-free property, energy conservation

property,” living environment, housing area, andmaintenance management conservation scenarios.
Regarding existing housing, although reform for stock
durable to long term use shall be promoted from theseview points, matters for which handling similarly to newresidential building are difficult and deliberations suitablefor existing housing will become necessary.
NILIM has implemented research and development
aiming for configuration of a target level of capability toequip housing for utilization over a long duration of years,
including the formation of multi-generation utilization
type super-long-term housing and housing land, and theevaluation standard for long term quality housing has
been prescribed based on its result. For the reform
acceleration for existing housing, we have continually
been grappling with preparing evaluation standards andarrangement for reform technologies.
Aiming for quality stock formation and distribution
promotion, I will exemplify our research anddevelopment which have been carried out in regard toevaluation for existing technologies, reform technologies
and so forth in the following.
1) Promotion of distribution for existing housing:
Development of capability evaluation technology for
housing or the like (2011—2014)
In order to contribute to distribution of existing housing,market environment improvement, in cases where there isno plan or the like for existing housing, to readily
comprehend its structure, materials or the like, andcarrying out the development of technology to efficiently
evaluate its performance and research and development
to contribute to distribution of existing housing withappropriate information.
Specifically, we have been carrying out (1) improvementof design information using three dimensional measuring
technology or the like, (2) establishment of methods toestimate materials/framing or the like for existing housing,(3) comprehension of degrading phenomenon in existing
housing, (4) research and development for evaluating theperformance of existing housing.
2) Development of energy consumption evaluation
methods in accordance with categories of housing (2010– 2014)
Of Japan’s energy consumption, housing and building
structure occupy 1/3, about half of it is regarded asstemming from energy for housing, so for the reductionof energy consumption, the promotion of reform forexisting housing for energy conservation is a big issue.
However, the present status is a situation where the effectcomparable to reform construction cannot be indicated,
so for its promotion, the development of a method inwhich the reduction effect of energy consumption volume
can quantitatively be illustrated in energy conservation
construction is required.
For this reason, based on research or the like forcasing/specification of equipment for each generation, wewill develop a simple forecast method for energy
reduction effects, as well as backing up deliberations forenergy conservation reforms of housing owners, andcarried out the development for more detailed analysis
method of energy conservation reform and compiled it asa technological sheet.
We will publicize this result as an energy guideline, andurge energy conservation reform for existing housing.
4. Assignment for the future
The stock countermeasure is made a big subject for thelatest policy related to the Ministry of Land,Infrastructure, Transport and Tourism. Not only civilengineering facilities, but also buildings and housing arethe same.
As a measure at a view point of housing reform for theformation of quality housing stock, although I
exemplified two research subjects above, there are plentyof research subjects to be tackled aiming for theformation of quality stock and its appropriate
management in addition to those.
The evaluation for housing in the existing housing market
in Japan is said not to reflect its capability held.
Quality housing is produced for the formation of quality
stock, maintenance to keep its performance is firmly
carried out; in addition, it is fairly evaluated and a market
to reflect on the value of existing housing shall be formed.
If the market grows to a rewarding one responding tostriving for maintenance, it is considered to stimulate
investment for creating quality stock.
NILIM also considers contributing to realization ofstock-type society through research and development.
[Sources]
1) Statistical research for housing/land
2) Statistical research for housing start3) Homepage of the Ministry of Land, Infrastructure,
Transport and Tourism (Housing Bureau)