Bedrooms, living rooms, toilets, kitchens and other auxiliary rooms can be arranged in layers, and the traffic between the upper and lower floors is not connected by public stairs, but by small stairs in the user's room. The duplex residence is a residence occupying two floors, with internal stairs connecting the upper and lower floors; Generally, the living room, kitchen, dining room and toilet are arranged on the first floor. It is better to have one bedroom, and the bedroom, study and sanitation are arranged on the second floor