Minimum Land Area & Height Limit

Minimum Land Area (Building Standards Act: Article 53-2)

If the city plan stipulates a minimum land area for a building, no building can be built unless the area exceeds that limit.　​However, this does not apply to land areas that were below the minimum before the restriction was imposed.

Height Limit

5-1 Diagonal Line Restriction　​(Road, adjacent land, north side) (Article 56 of the Building Standards Act)

Specific restrictions are determined by the site's zoning and designated floor area ratio. There may be mitigation measures depending on the setback distance from the boundary line, the difference in elevation, and the surroundings (park, river, railroad tracks, etc.).

(1) Road Diagonal Restrictions
If the property borders a road (there is a road boundary line), the height will be restricted according to the distance from the boundary line on the other side of the road.

(2) Adjacent Land Diagonal Restrictions
If the site borders the neighboring land (there is a neighboring land boundary line), the height restriction will be applied according to the distance from the neighboring land boundary line. This does not apply to the 1st and 2nd class low-rise residential areas.

(3) North Side Diagonal Restrictions
Height restrictions are applied according to the distance in the north direction to the boundary line on the opposite side of the road or the boundary line of the neighboring land.　This applies only to Class 1 and Class 2 low-rise residential areas and Class 1 and Class 2 high-rise residential areas where there are no sun-shading restrictions.

‐	Road Diagonal Restrictions	Adjacent Land Diagonal Restrictions	North Side Diagonal Restrictions
1st and 2nd Class Low-Rise Residential Area	○	✖	○
​1st and 2nd Class Low/Medium-Rise Residential Area	○	○	○*
1st/2nd Class and Quasi Residential Area	○	○	✖
Urban Commercial Area ​Commercial Area	○	○	✖
Quasi Industrial Area Industrial Area ​Industrial-Use Only Area	○	○	✖

5-2 Absolute Height Restrictions (Article 55 of the Building Standards Act)
In the 1st and 2nd class low-rise residential areas, the height limit of buildings (10m or 12m) is set by city planning.

5-3　High Altitude Areas (Article 55 of the Building Standards Act)
The height of the building must conform to the requirements of the city plan for high altitude zones.

• The restrictions vary from one local government to another, but in most cases, the restrictions are a combination of diagonal restrictions and absolute height restrictions, and mitigation measures, if any, are specified in the city plan.​