Building density, along with building-to-land ratio and floor area ratio, is an index that could quantitatively inform us the volume of a city. Conventionally, method of measurement for building density defined a gross data which took into account of existing network such as streets and rivers. However, this research considers a way of reading urban forms through utilizing what is defined here as "building density on block", which measures the number of buildings within net zones enclosed by streets.
Carrying out this process using maps of Nagoya from differing years, enabled clarification on density changes occurred in this city in the past post-war 50 years.
