House with Membrane Roof, Yuko Nagayama & Associates, Shohei Yoshida & Associates, and others

The architects provided a textual description. It is a private residence in Tokyo’s crowded residential district. The home was designed so that the owner can relax in his own space and enjoy the day-to-day activities of hosting friends and camping in the city. The owner’s nomadic lifestyle is reflected in the home’s adaptability and functions.

Except for the slender frontage that faces the street, the site is enclosed on all sides by the buildings that surround it. Light is brought in from above because this site condition prevents large exterior wall openings. The atrium carries light down to the ground floor and the membrane roof lets soft, diffused light into the second floor.

While the public area on the second floor is well-lit, private areas like the bedroom and bathroom on the ground floor lack natural light. It is a peaceful place to unwind and sleep, similar to being inside a cave with low lighting. In place of an exterior garden, an indoor garden with a tree is installed in the skylit atrium to maximize the building footprint within the site boundary. Instead of only observing nature through the window, the owner can live in direct contact with it by bringing the garden inside.

The general rooftop is developed in a bendable film material to make a three-layered distorted surface. The structure and thermal insulation are sandwiched between the upper and lower membranes of this roof’s double-membrane structure. The ceiling is lined with semi-circular light tubes because the lower membrane is hooked to the ends of structural beams shaped like Ts in a catenary curve. In order to maintain a comfortable indoor environment, the air space within the roof serves as the thermal insulation layer and provides natural ventilation by circulating air from the bottom to the top.

Despite the membrane roof’s lack of direct view of the sky, changes in light can be used to detect environmental changes. The space gradually gets brighter as the sun rises, and the warm light gradually makes it redder at night. The brilliance additionally changes among radiant and overcast days. The roof transforms one’s senses and transmits changes from the outside to the inside, acting like a skin layer.