PURPOSE: To enhance habitability and safety by laying out a bed room and a dressing room so that it may be next to an air-well void for lighting and ventilation and laying out a bath room so that it may be next to the dressing room and forming one room type dressing room which includes a toilet and a washstand.

CONSTITUTION: An air-well void 8 is installed so that it may be next to a dressing room 6 and a bath room 7. A bed 9 is installed to a bed room 3 which serves as a living room. The dressing room 6 is arranged to be one room type which incorporates integrally a toilet 10 and a washstand 11 where a water- related space is under double floor structure. The toilet 10 and the bath room 7 are laid out close to the living room which serves as the bed room 3 so that aged people may have direct access to the toilet 10 and the bath room 7 at the shortest distance while they may enter the dressing room 6 easily even riding in a walker or a wheelchair. Specific consideration must be given to the space and the width of a door while an offset area must be eliminated as well.