Tachikawa Annex is a modern single-family house located in Tokyo, Japan, designed in 2020 by MDS Architectural Studio.

Description
The building is an annex to the main building we designed about 10 years ago as corporate headquarters of a clothing maker and the owner?s house. The site stretches over several zones under different regulations, which led to different structure or height variations. Our choice, in contrast to the five-story RC main house which rose vertically, was to design a light wooden building in the widened area in the back of the site, in the category I exclusively low-rise residential zone. The exposed timber frame structure is composed of the lower structure with two-story posts, and the roof structure with 90 by 90 mm timber struts which, supporting the purlins, shift in angles and form HP surfaces. These two structures?the lower and the roof?together with the intervening floor frame in between create a unique and generous single space on each level. The ground floor is used for a warehouse as well as a photo studio, while the upper floor is a second house of the owner. Optimized for the purpose, the ground level has less openings to let in only modest lights into the dark space. In contrast, the upper level has full openings on the gables to brighten the space for the residential purpose. Considering the main facade was on the west, we had to cope with low-angle sun exposure as well as to block views from frequent monorail traffic. T...