hyan adapts 1970s timber frame into live-work residence on the hills of hayama

the existing columns and beams are retained and structurally strengthened, while the interior is reorganized around a double-height living room and a recessed doma created from a former tatami room.

HYAN edited by christina vergopoulou November 13, 2026 3 min

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HYAN SEISMICALLY RETROFITS AND REMODELS 1970S TIMBER RESIDENCE

Located in a hillside residential district of Hayama, Kanagawa, Japan, Green Sandwich House is the adaptive reuse of a late-1970s timber residence converted into a combined home and studio for architect Anna Naganuma and designer Shohei Hasegawa of Japanese architecture practice HYAN. Rather than demolishing the pre-1981 seismic-code structure, the studio retained the undamaged timber columns and beams, integrated seismic reinforcements, and reconfigured the interior layout to support overlapping domestic and studio functions.

hyan adapts 1970s timber frame into live-work residence on the hills of hayama - 1 — Green Sandwich House is a renovated 1970s timber residence in Hayama | all images ©Katsuhiro Aoki

DOUBLE-HEIGHT LIVING ROOM AND RECESSED DOMA ORGANIZE OPEN PLAN

Studio HYAN anchors the ground floor around a central double-height living room that connects the kitchen, pantry, study, garden, and a newly formed doma. Carved from a former tatami room by removing the traditional matting and altering the floor elevation, the doma incorporates a converted closet nook to serve as a multi-purpose threshold for working, hosting, and lounging. Instead of relying on solid partitions, the floor plan delineates programmatic zones through changes in floor level, sightlines, material transitions, and movable textiles. Custom curtains designed by textile artist Haruka Shoji frame the large openings and the doma, filtering daylight and garden views throughout the day. New functional surfaces, including the kitchen countertops and washbasin, are finished in hand-ground, in-situ terrazzo, establishing a tactile contrast against the exposed, aged timber frame.

hyan adapts 1970s timber frame into live-work residence on the hills of hayama - 2 — a double-height living room anchors the ground floor, promoting natural ventilation and light distribution

hyan adapts 1970s timber frame into live-work residence on the hills of hayama - 3 — large glazed openings visually extend the central living space toward the surrounding greenery

hyan-renovation-1970s-timber-house-studio-hayama-japan-designboom-1800-3 — original structural columns and ceiling beams are retained and left exposed throughout the interior

hyan adapts 1970s timber frame into live-work residence on the hills of hayama - 4 — the kitchen island and counters are finished in terrazzo that contrasts with the warm timber frame

hyan adapts 1970s timber frame into live-work residence on the hills of hayama - 5 — detail view showing the aggregate texture of the cast-in-place terrazzo worktop against wooden joinery

hyan adapts 1970s timber frame into live-work residence on the hills of hayama - 6 — a custom washbasin in matching hand-ground terrazzo maintains material continuity across wet zones

hyan-renovation-1970s-timber-house-studio-hayama-japan-designboom-1800-2 — custom curtains act as permeable partitions that modulate light and garden views

hyan adapts 1970s timber frame into live-work residence on the hills of hayama - 7 — a former tatami room turns into a recessed doma by stripping the matting and adjusting floor levels

hyan adapts 1970s timber frame into live-work residence on the hills of hayama - 8 — the double-height living volume preserves acoustic and visual connection across floors

hyan adapts 1970s timber frame into live-work residence on the hills of hayama - 9 — the upper floor tile-clad bathroom overlooks the surrounding hillside views

hyan-renovation-1970s-timber-house-studio-hayama-japan-designboom-1800-4 — the renovation demonstrates an incremental approach to updating Japan’s aging residential housing

project info:

name: Green Sandwich House / A 1970s House Renovation
architect: HYAN | @hyan_studio

lead architect: Anna Naganuma

lead designer: Shohei Hasegawa

construction: Deguchi Tategu-ten

textiles: Haruka Shoji

location: Hayama, Kanagawa, Japan

site area: 271.18 sqm

floor area: 106.2 sqm

photographer: Katsuhiro Aoki | @katsuhiroaoki

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