協働ワークス Tokyo micro-architecture · design-build

The lot is the puzzle.
The house is the proof.

We design and build architect’s houses on the sites Tokyo forgot — nine-tsubo slivers, corners cut twice, flags on two-metre poles. Three are finished and for sale. Every millimetre has a job.

See the three houses How we solve a lot

smallest site: 9.0坪
narrowest frontage: 2,700mm
cheapest tsubo: ¥3.97M

The drawings need JavaScript; the facts don’t. Three houses: a 2.7 m-wide slice in Kyōjima, an L-shaped corner in Nezu, a tower on a Sangenjaya flag lot. All details below.

01 間口 — the width

First, the width.

House 01’s entire street face is 2,700 mm. The sedan parked outside is 4,890 mm long. The house is two metres narrower than the car — and inside it: three floors, a stair full of drawers, a bath, and a living room with a three-metre ceiling.

Width is what Tokyo ran out of. Depth and height it still has plenty of. Our whole practice fits in that sentence.

Street elevation of House 01, drawn 1:1 beside a standard sedan and a 1,700 mm neighbour.

02 三軒 — three houses

Three lots nobody wanted.
Three houses everybody asks about.

Each drawing below is the real house, floor by floor. Scroll to it and it takes itself apart.

House in Kyōjima 京島の家

The slice — 2,700 mm of street, three floors of house

for sale

Nine tsubo between two party walls. The move: one room per floor, so no floor owes a corridor. The staircase is a chest of drawers — six of them, pans to winter coats — and the skylight above it drops light all the way to the genkan, three storeys down.

The living room is on top, where the sky is. Its ceiling is 3,000 mm because you spend your evenings there, and the bath’s is 2,200 because you spend eleven minutes.

House in Kyōjima specifications
site	9.0坪 · 29.7 m²
frontage	2,700 mm
plan	3F + loft · timber (木造)
floor area	44.6 m² · 13.5坪 · 25.5帖
ceilings	2,200 / 2,400 / 3,000 · loft 1,450
station	Keisei-Hikifune · 6 min walk
price	¥58,800,000 = ¥6.53M /坪

House in Nezu 根津の家

The corner — two streets, two skies, one cat

under offer · 商談中

A corner lot gets light from two directions, so the plan is an L that turns its back on the neighbours and opens both arms to the streets. The notch it leaves behind is a pocket court: three stones, one maple, enough.

Upstairs sleeps. The roof is the third room — a cedar-decked terrace with a metre of parapet, which is exactly cat height. She isn’t included in the sale. She has, however, stopped negotiating.

House in Nezu specifications
site	11.5坪 · 38.0 m² · corner
frontage	4,900 mm × two streets
plan	2F + roof terrace · timber
floor area	39.8 m² · 12.0坪 · terrace 9.1 m²
ceilings	2,300 / 2,500 · terrace: sky
station	Nezu (Chiyoda line) · 4 min walk
price	¥79,500,000 = ¥6.91M /坪

House in Sangenjaya 三軒茶屋の家

The flag — a two-metre approach, then a tower of quiet

for sale

A hatazao-chi — flag lot. You buy a pole of path and a field of land hidden behind someone else’s house, with neighbours on three sides. The market discounts it hard. The sky does not: it’s exactly as available as anywhere in Setagaya.

So the house looks up. One 1,050 mm skylight feeds a light well that falls past the void in the living floor onto the kitchen table. No window faces a neighbour; nothing needs a curtain. It is the quietest house we have ever built, nine minutes from one of the loudest crossings in the ward.

House in Sangenjaya specifications
site	13.1坪 · 43.3 m² (flag lot)
approach	2.0 m wide × 6.5 m
plan	3F tower · timber
floor area	34.6 m² · 10.5坪 · 18.5帖
ceilings	2,200 / 2,700 / 2,400
station	Sangen-jaya (Den-en-toshi) · 9 min
price	¥52,000,000 = ¥3.97M /坪

03 手法 — method

How we solve a lot.

Four habits, drawn. They appear in every house above; they will appear in yours.

The stair is a cupboard

A staircase spends 4 m² of your nine tsubo. So it earns its keep: every riser fronts a drawer. Pull one — click or focus and press enter.

Kaidan-dansu: the Edo-period stair-chest, re-detailed in birch ply. House 01 has six drawers; the deepest holds a duvet.

The sky is the window

When neighbours stand on three sides, light comes from the fourth: straight up. Tokyo’s noon sun swings from 31° in December to 78° in June — the well is shaped for both.

Section through House 03. Summer sun reaches the kitchen floor directly; winter sun is caught by the well’s white north wall and bounced down.

Height is a budget

Regulations cap the building; gravity stacks the floors. What’s left is a fixed sum of millimetres — we spend them where you stand and save them where you sleep.

Every ceiling in the three houses, to scale. The blue room is each house’s tallest — always the one you live in longest.

Where we build

Dense wards are where small lots exist — and where small houses make sense: the city is your second floor plan. Each square is a thousand people per km².

Residential density, 2025 ward statistics. We build where the squares are.

04 価格 — prices

Per tsubo, out loud.

Tokyo prices land by the tsubo, so we will too. No “price on application.” The number is the number; the notes are why.

house	price	site	¥ / 坪	the honest note
01 · Kyōjima	¥58,800,000	9.0坪	¥6,530,000	narrow costs less than small
02 · Nezu	¥79,500,000	11.5坪	¥6,910,000	corner premium, stated plainly
03 · Sangenjaya	¥52,000,000	13.1坪	¥3,970,000	the flag discount is real — the sky is not discounted

Prices include design, construction, and our two-year defects warranty. Taxes and registration separate, as everywhere. Financing referrals to two banks that understand 9-tsubo appraisals.

05 見学 — inquire

Stand inside one.

Drawings argue; floors convince. Open viewings run Saturdays 10:00–16:00 in 40-minute slots — one household at a time, because the houses are honest about their size and so are we.

If you own an impossible lot and want it solved, say so in the message. Those are our favourite emails.

KYŌDŌ WORKS 協働ワークス
2-14-6 Kuramae, Taitō-ku, Tokyo 111-0051
03-3866-1720 · mado@kyodo.works