To provide a method of constructing a building based on a previously unknown new idea of construction.

The method of constructing a building at a construction site includes treating the building A to be constructed as an assembly of sections B each with a predetermined volume or area, then treating each section B as site position data corresponding to the position of the section B at the construction site and a number of design and arrangement data corresponding to the arrangement characteristic of the section B in terms of design, and forming each section B at the construction site according to the site position data and the design and arrangement data to thereby construct the building A.