Tokyo is known for its oddly angled buildings such as the sloping roof’s on the the row of buildings in the center of the picture. But why?

Building regulations typically allow the land owner to build to a percentage of the land footprint and a multiple of that for the total interior size of the building (small balconies are not added to the total square meterage so you tend to see more of them that is strictly necessary).

A 100 square meter piece of land might be stipulated at 80% / 160%: not more than 80% of the land can be built on; and the total meterage of the land cannot be more than 160% of the footprint i.e. 160 square meters. There are also regulations relating to the distance to the next building – in an effort to minimise the impact of post-earthquake fires. The slicing and peculiar angles come from natural lighting regulations – where neighbours have the right to the same level of natural light with the new building, as what previously stood there. Builders optimise the interior size of the building by optimising the meterage by taking up as much of that space as possible, even if it means slicing off corners to provide light-access. Hence a very Tokyo centric sense of building shape – since it’s in Tokyo that where the most building optimisation takes place.

In years gone by I came very close to buying a plot of land in Mishuku and designing the building to go on it. The novelty in the Japanese housing market is that many buildings are designed for a lifetime of 20 to 25 years before being torn down – and the process is surprisingly affordable.

Photo: Shibuya, on last week’s stopover.

See also: the urban geometry thread.