Housing Conditions 3-6: Disaster prevention and housing

As of 2018, of the houses including non-wooden buildings, the number of houses built before 1980, which was before the establishment of the new seismic standards under the Building Standards Law, was 298,400 units in Yokohama City as a whole, accounting for 18.1%. It has decreased from 2013 at the time of the previous survey (336,150 units, 21.
Isogo Ward accounted for 28.2% of the houses built before 1980. On the other hand, the small percentage was 7.4% in Tsuzuki Ward   (Figure 3-6-1).

Figure 3-6-1 Percentage of houses built in each ward before 1980

Materials: Ministry of Internal Affairs and Communications, “2018 Housing and Land Statistics Survey”

The number of wooden houses built before 1980 was 150,700 in Yokohama City as a whole, accounting for 9.1%, a decrease from 2013 (174,830, 11.1%) at the time of the previous survey. .
By distinction, Sakae Ward has the largest percentage of wooden houses built before 1980, accounting for 13.5%. On the other hand, the small percentage was 4.3% in Tsuzuki Ward   (Figure 3-6-2).

• Reference Materials[Wooden Housing Seismic Diagnostics Dispatch Business]

Figure 3-6-2 Percentage of wooden houses built before 1980 in each ward

Materials: Ministry of Internal Affairs and Communications, “2018 Housing and Land Statistics Survey”

According to the diagnosis results of houses that have applied for wooden house seismic diagnosis conducted by the city (for houses built before applying the new seismic standards), about 70% are "highly likely to collapse." It has been determined that more than 80% of wooden houses have some danger, including "possible to collapse."
Conversely, the number of houses diagnosed as "do not collapse" is very low at 1.3%, and it is hoped that the use of seismic retrofitting work using the city's subsidy system will increase. (Fig.3-6-3).

Fig. 3-6-3 Wooden House Seismic Diagnosis Results (Yokohama City)

Materials: Results of Wooden Seismic Diagnosis by City of Yokohama, Housing and Architecture Bureau