This study aims to validate the vacancy rate and number of vacant houses in the Housing and Land survey. Determining the actual vacancy rate and numbers of vacant houses contributes significantly to housing policy. No preceding research has been conducted with the same aim.
The research method is as follows.
1. Confirm the vacancy survey method utilized by the Housing and Land survey.
2. Compare the results of the Ministry of Land, Infrastructure, Transport and Tourism vacancy survey and Housing and Land survey.
3. Compare the results of the house vacancy survey by municipality and Housing and Land survey.
4. Compare vacancy rates obtained using the number of census households and from the results of Housing and Land survey.
5. Compare the results of the vacancy rate using the SUUMO-ZENRIN data for Tokyo's 23 wards and Housing and Land survey.
Based on these results, the validity of the vacancy rate and number of vacant houses in the residential land survey is examined.
The results of the research are as follows.
1. The vacancy survey method of Housing and Land survey relies on a visual inspection overview.
2. The vacancy rate in the Ministry of Land, Infrastructure, Transportation and Tourism's vacancy survey (6.7－8.9%) is lower than that in Housing and Land survey (over 10%). The Ministry's vacancy survey stated that visual inspection is an inaccurate survey method.
3. The vacancy rate in the municipality's vacancy survey (1.6－7.4%) is lower than that in Housing and Land survey (10.3－14.6%). Most municipal vacancy surveys are conducted for all houses (Table 1).
4. The vacancy rate obtained using the census household number (2008: 10.0%) is lower than that in Housing and Land survey (2010: 13.9%) (Fig. 1).
5. The vacancy rate using the SUUMO-ZENRIN data (6.9%) is lower than that in Housing and Land survey (12.3%) (Fig. 2).
- The SUUMO data cover 80% of the common housing residences in Tokyo's 23 wards (Table 2).
- In Tokyo metropolitan area, the vacancy rate of housing with an area less than 25 square meters is high (12.2%) (Table 3).
- In Tokyo metropolitan area, the vacancy rate of houses built after 1996 is high (10.1%) (Table 3).
The conclusions are as follows.
1. The vacancy rate in Housing and Land survey is likely to be exaggerated.
2. The actual vacancy rate is likely to be 10% or less.
3. The actual number of vacant houses is likely to be 4－5 million.
Future tasks are as follows:
1. To find an appropriate vacancy rate for each area.
2. To find a simple and accurate method of identifying vacant houses.
