PURPOSE: To construct a variety of buildings easily using one type of one or multiple construction sheets, and cover the ceiling part of the buildings surely.

CONSTITUTION: Using a building construction sheet 10 which is detachable and in which a buoyancy member is installed, a ceiling part 44 is coated on a temporary scaffold 46 at the periphery of the ceiling part 44 of a building 42. After the construction of the coated area has been completed, the temporary scaffold is constructed, a building construction sheet is moved upward, and the coated area is re-constructed to construct the building.