tsutsumi and associates reveals 1979 irimoya-style house's timber framework

Tsutsumi and Associates Renovate 1979 Timber-Framed house

The single-story irimoya-style house, originally constructed in 1979, has been transformed by Tsutsumi and Associates into a combined shop and guesthouse. The renovation involved setting back the guesthouse wall to create a catwalk, revealing the original timber frame. Natural light from glass roofing tiles illuminates the structure, highlighting elements that were previously concealed.

Located near Fukuma Beach in Japan, the project site was discovered by a client who envisioned converting the old house into a multifunctional space. Despite showing signs of inexpensive renovations, such as printed plywood exterior walls and polycarbonate corrugated roofing, the original wooden structure was well-crafted with knotless cypress pillars and large domestic pine beams.

all images by © Yashiro Photo Office

irimoya-style house’s restoration Enhances Structural Integrity

The renovation process involved retaining the original structure’s integrity while removing non-structural pillars that obstructed movement. The team replaced the bases of pillars embedded in concrete and added structural plywood where necessary to ensure load-bearing capacity. Horizontal rigidity was achieved by securing the rafters with braces. The earthen walls provided adequate insulation, supplemented by glass wool in new walls and extruded polystyrene foam beneath the flooring.

The irimoya roof structure posed a challenge due to its high ridge beam. To avoid creating a massive 5.3-meter-high wall that would lack a human scale and obscure the timber frame, the design set back the upper part of the large wall on the guesthouse side. This created a 2.1-meter-high catwalk, offering a lowered ceiling height of 2.33 meters in the shop. The catwalk allows natural light to enhance the visibility of the timber frame. This approach reverses the typical architectural focus by exposing the timber structure that was once hidden and concealing elements that were previously visible. This design choice celebrates the robust form of the timber frame.

the 1979 irimoya-style house transformed into a combined shop and guesthouse by Tsutsumi and Associates

the renovation reveals the original timber frame through a setback in the guesthouse wall

glass roofing tiles illuminate the timber structure with natural light

the original structure features knotless cypress pillars and large pine beams

bases of concrete-embedded pillars were replaced, and structural plywood added for load-bearing capacity

rafters were secured with braces to achieve horizontal rigidity

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project info:

name: Timber framing of 1979
architects: Tsutsumi and Associates

location: Fukuma Beach, Fukuoka Prefecture, Japan

photography: Yashiro Photo Office

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edited by: christina vergopoulou | designboom