Tachikawa ANNEX House
© Koji Fujii / TOREAL

TACHIKAWA ANNEX HOUSE

MDS

ARCHITECTS
MDS

LOCATION
Tachikawa, Tokyo, Japan, Japan

MANUFACTURERS
ARC-X, Ps Company, Sanei, Skantherm GMBH

LEAD ARCHITECTS
Kiyotoshi Mori, Natsuko Kawamura (MDS)

CATAGORY
Mixed Use Architecture, Warehouse, Houses

AREA
205 m²

YEAR
2020

Details between House and Warehouse - The building is an annex to the main building we designed about 10 years ago as the 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.

Tachikawa ANNEX House
© Koji Fujii / TOREAL
Tachikawa ANNEX House
© Koji Fujii / TOREAL

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 at 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.

Tachikawa ANNEX House
© Koji Fujii / TOREAL
Tachikawa ANNEX House
© Koji Fujii / TOREAL

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.

Tachikawa ANNEX House
© Koji Fujii / TOREAL
Tachikawa ANNEX House
© Koji Fujii / TOREAL
Tachikawa ANNEX House
© Koji Fujii / TOREAL

Optimized for the purpose, the ground level has fewer 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 residential purposes.

Tachikawa ANNEX House
© Koji Fujii / TOREAL
Tachikawa ANNEX House
© Koji Fujii / TOREAL
Tachikawa ANNEX House
© Koji Fujii / TOREAL
Tachikawa ANNEX House
© Koji Fujii / TOREAL
Tachikawa ANNEX House
© Koji Fujii / TOREAL

Considering the main facade was on the west, we had to cope with low-angle sun exposure as well as block views from frequent monorail traffic.

Thus, we adopted translucent polycarbonate with a thick void layer for efficient insulation and thermal protection. As a result, we created a space without shadows, filled with subtle light.

Tachikawa ANNEX House
© Koji Fujii / TOREAL
Tachikawa ANNEX House
© Koji Fujii / TOREAL

As the bearing ground level was only about 1m below the surface, we put the mat foundation on that level and used the slab as the ground floor.

The soil dug for the foundation was mounded up to the upper level to connect the residential floor with the ground. The light facade with a full opening—through translucent—gives a feel of a temporary facility and opens to the town.

This annex, surrounded by the main building and other detached houses, aims at presenting a new and unclassified townscape in the way it’s used, the scale, and how it emerges as architecture.

Tachikawa ANNEX House
© Koji Fujii / TOREAL


Tachikawa ANNEX House
Site Plan
Tachikawa ANNEX House
Plan


Tachikawa ANNEX House
Diagram 01

Tachikawa ANNEX House
Structure Diagram
Tachikawa ANNEX House
Foundation Diagram
Tachikawa ANNEX House
Perspective Section

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