deformed roof house in rural japan receives greenhouse-like extension

japanese architecture firm yoshichika takagi + associates presents the renovation of a rural 1970s-era home into the two-family deformed roof house. after multiple renovations over the decades, the volume of the preexisting structure had naturally developed into an unusual geometry. buildings such as these, with a roof structure irregular in profile, are commonly known as the ‘deformed roof’ type. the design team explains that this typology ‘can be seen often in hokkaido, but it is difficult to call them beautiful, and cannot be seen out of hokkaido. it could be called a vernacular and anonymous kind of design.’

all images by ikuya sasaki

during the renovation process, yoshichika takagi’s deformed roof house was redeveloped through two main strategies: the house was first stripped to its frames, exposing the original timber structure. a translucent, offset secondary skin was added, introducing a full-height light well, six feet in width, which serves as the primary circulation channel. this extension softly connects the two stacked homes while offering an interstitial shared spaces, suspended between the two facades. the narrow zone expresses qualities of a light-filled greenhouse as it is only partially conditioned and is finished with a dirt floor.

before the introduction of this deformed roof model, built with a wooden structure, builders in this area had typically constructed metal framed ‘triangular roof’ houses. one of the main reasons for the eventual turn toward the deformed roof model and away from the more normative type was a mid-century economic shift which allowed builders to make use of timber as the primary material. another reason is the advancement of sheet-metal technology, which made it possible to re-adapt roofs during renovations regardless of the formal complexity. ultimately, the rural area has seen an extensive range of roofline profiles following this gradual stylistic development.