---
title: "Two families, one volume, a game of Tetris: how a constraint became a plan"
locale: "en"
url: "https://irz.fr/en/articles/woonpioniers-cohouse-tetris-en"
markdown_url: "https://irz.fr/en/articles/woonpioniers-cohouse-tetris-en.md"
category: "craft"
tags: ["architecture", "housing", "constraint", "timber", "co-living"]
published_at: "2026-08-17T09:25:00.000Z"
author: "Noé Lambert"
translation: "https://irz.fr/fr/articles/woonpioniers-cohouse-tetris-fr.md"
---

# Two families, one volume, a game of Tetris: how a constraint became a plan

The Dutch municipality would only allow one building volume for two families. Woonpioniers answered by interlocking the two homes around each other “like a game of Tetris”, and the constraint became the plan.

Two families bought a riverside plot in the Dutch village of Cothen and wanted to build homes on it. The municipality had one condition: both homes had to fit inside a single building volume.

Amsterdam studio Woonpioniers turned that constraint into the design.[2](https://www.woonpioniers.nl/) The result, CoHouse, is a timber volume containing two interlocking dwellings, each rotated around the other — a layout the studio describes as “a game of Tetris”.[1](https://www.dezeen.com/2026/08/16/woonpioniers-cohouse-in-cothen/)

> Illustration: Exterior of the CoHouse timber volume in Cothen. One gabled volume reads as a single building from the street. Credit: [Woonpioniers / Dezeen](https://www.dezeen.com/2026/08/16/woonpioniers-cohouse-in-cothen/).

## The constraint draws

The single-volume rule might have produced two identical flats stacked or split down the middle. Instead, Woonpioniers used the constraint as a tool. “To make the most of the garden, views, privacy and sunlight, the two homes were carefully rotated around each other like a game of Tetris,” studio partner Leen Bogerd told Dezeen.[1](https://www.dezeen.com/2026/08/16/woonpioniers-cohouse-in-cothen/)

The interlocking means each home gets its own relationship to the site: one looks over an enclosed garden, the other over the surrounding landscape. Sharing a volume did not mean sharing a view or a sense of place.[1](https://www.dezeen.com/2026/08/16/woonpioniers-cohouse-in-cothen/)

> Illustration: Interior of one of the CoHouse dwellings. Each home keeps its own orientation, privacy and light inside one volume. Credit: [Woonpioniers / Dezeen](https://www.dezeen.com/2026/08/16/woonpioniers-cohouse-in-cothen/).

## Constraint number two

Both families asked for a low-carbon build, which gave the project a second set of constraints. The structure is a timber frame with cross-laminated timber floors and wood-fibre insulation, and the party floor between the homes uses a bio-based acoustic build-up. Energy comes from ground-source heat pumps, a heat-recovery ventilation system and a solar roof, with external shading on the south and west facades.[1](https://www.dezeen.com/2026/08/16/woonpioniers-cohouse-in-cothen/)

The whole project is 237 square metres across the two homes.[1](https://www.dezeen.com/2026/08/16/woonpioniers-cohouse-in-cothen/)

> Illustration: The timber frame and CLT floors of CoHouse. Timber frame, CLT floors and a bio-based party floor between the homes. Credit: [Woonpioniers / Dezeen](https://www.dezeen.com/2026/08/16/woonpioniers-cohouse-in-cothen/).

The two homes are not identical either, and that is part of the method. Each was tailored to its family's needs, with floor plans oriented to what that household values — the garden in one case, the wider landscape in the other. The Tetris metaphor works because the pieces fit while remaining different shapes.

The interlocking also solves a problem that co-housing usually makes visible: how two households share a building without feeling like they share a life. Each home has its own entrance and orientation, and the overlap happens where it costs least — in the middle of the volume, where the two plans interleave like pieces of a puzzle.

The lesson is an old one, and it keeps being worth restating: a rule that looks like a restriction — one volume, low carbon — can do more design work than a blank page. The constraint did not limit the plan. It gave the plan a shape.

A municipality that insists on a single volume is often read as an obstacle. Here it reads as the brief. The families still got two distinct homes; they just had to be built as if they were one. That inversion — turning the rule into the method — is the part worth copying.

## References

1. [Starr Charles, Woonpioniers models adjoining Dutch homes on “a game of Tetris”, Dezeen, August 2026](https://www.dezeen.com/2026/08/16/woonpioniers-cohouse-in-cothen/)
2. [Woonpioniers, studio](https://www.woonpioniers.nl/)