From June 1, 2015, the Minato City Government in Tokyo introduced allowances to building volume ratios to encourage the re-development of old, non-earthquake resistant apartment buildings.
Apartment buildings that meet certain requirements and receive government approval may be re-built to a larger size than would normally be allowed on that block of land. An allowance of up to 200% may be given if conditions are met. This may bring the maximum possible building volume ratio (yosekiritsu) up to 1,000%, depending on zoning.
- Building inspection shows that current structure does not meet new earthquake codes (introduced in June 1981).
- New building area is to be less than 10,000 sqm (for buildings over 10,000 sqm, Tokyo City Government must provide approval).
- Land size must be over 300 sqm (neighbourhood commercial or commercial zones), 500 sqm (Residential, mid/high-rise oriented residential zones), or 1,000 sqm (Category 1 exclusively low-rise residential zone).
- Road width must be over 6 meters (8 meters in neighbourhood commercial or commercial zones).
- Road frontage must be at least 10 meters.
- A minimum of 10% of the land must be open public space.
Minato-ku has a relatively low density when compared to Manhattan. According to a study by Mori Building in 2011, the average building volume ratio in Minato-ku is 302.3%, versus 631% in Manhattan’s Upper East Side. The main factor limiting density in central Tokyo is the large number of narrow streets.
Soruce: Minato City Government Website, June 15, 2015.