To provide a dwelling house which enables an open ceiling space to be efficiently lit without the use of expensive lighting fittings, and facilitates the construction and maintenance of the lighting fittings.

A decorative laminate sheet 4 with high visible light reflectance is mounted on the ceiling surface of the open ceiling space 3 in which upper and lower floors vertically communicate with each other, and the lighting fittings 5 for lighting the sheet 4 are mounted on the side wall of the lower floor.