Structural EngineerHirokazu Toki, Takuo Nagai
ConstructorCo. Washin Architectural Firm
Text description provided by the architects. The project is a house and clinic in Dennenchofu Residential Area, at the southern periphery of Tokyo, Japan. Dennenchofu were planned based on Ebenezer Howard’s ‘Garden City’ concept and lots were being sold since 1923. Fifty percent building coverage was mandatory to secure garden space for each lot.
In the past it was populated with mansions built on large sites. However in recent years lots have been split by inheritance, reducing each lots’ space for gardens, to a point where there are no gardens at all. The site of the project was also divided by inheritance, which resulted in a ‘flag and pole’ site of about 90 m2. The lot is squeezed between adjacent houses with only a 2.5m wide alley as access from the street.
RAA started the design process by examining ‘flag and pole’ sites around the site. In general, houses were built in the ‘flag’ portion of the site, whereas the ‘pole’ portion were used as the entrance and parking space, leaving no space for a garden. Moreover, the regular approach, built in a densely populated area, resulted in minimum natural ventilation and light exposure.
Based on the afore-mentioned conditions, model studies and Computational Fluid Dynamics (CFD) simulations were done, with compliance to local codes and regulations. The challenge was to obtain a building mass that could make maximum use of its’ site’s shape that would allow optimum ventilation and natural light exposure, while also providing adequate space for a garden in the midst of the densely populated residential area.
The final mass manages to fuse the ‘flag’ and ‘pole’ portion of the site. The house curves horizontally and vertically, ensuring sun exposure and wind flow to every part of the house, from top to ground floor, outer to the depths of the house. The curved surface was made by fixing plywood on to the column, and the whole interior is clad in plywood.
The program includes a clinic (located on the ground level) attached to the residence. The elongated living space at the second floor continues to the terrace, which cantilevers over the parking space, providing view to the park on the opposite road. Third floor is dedicated to the bedrooms and rooftop. Beside the three-story house, southern part of the narrow site has been dedicated to a garden. In this way, the house has become a unique, contemporary interpretation of Ebenezer Howard’s ‘Garden City’ concept.