To provide a habitable room construction allowing easy reforming work by enabling a floor plan to be easily constructed with the use of L-shaped panels or three-sided panels inside a building frame constructed of concrete or reinforced concrete which makes it difficult to achieve dimensional accuracy, with the panels abutting against the inside of a wall skeleton so that the interior of the habitable room construction can be achieved irrespective of the dimension of the building frame.

The habitable room construction is characterized in that a floor plan is constructed inside a building frame constructed of concrete or reinforced concrete which makes it difficult to achieve dimensional accuracy, in such a way that L-shaped panels corresponding to wall faces have their respective vertical end faces made to adjoin to the inside of a wall skeleton.