Protoplain Architects Rebuilds Four Forest Restrooms in Taichung with Taiwan-Grown Bamboo

Public toilets are the buildings most visitors use and almost nobody remembers. In a national forest recreation area in Taichung, Taiwan, Protoplain Architects, led by Yu-Hsin Yeh, completed the Basianshan Natural Public Toilet in 2024. It is a set of four restrooms with a combined area of 362 m², and Taiwan-grown bamboo is the primary material across all of them.

What makes the project worth your attention is the method, more than the bamboo itself. Each of the four facilities was delivered through a different mode of construction: one new building, one renovation, one interior refurbishment and one canopy structure. Most clients in this position would roll out a single standard type across the whole park. This one treats each site as a separate problem with its own budget logic. A shared material vocabulary keeps the four answers related, so they read as a family without being identical.

A Disc of Bamboo over Earthen Walls

The best-known piece of the set is a round, bamboo-framed roof held above ochre rammed earth walls. The roof is a thin disc with ribs radiating outward, and it hovers over the enclosures without sealing them. From a low angle it looks almost weightless against the forested slope. The earth walls below are heavy and warm in colour, and they ground the composition.

The contrast is the point. The walls do the private work of screening stalls, and the canopy does the public work of shelter and signalling. A timber railing and a stepped path lead you onto a paved terrace. The restroom becomes a small clearing rather than a box you duck into and leave quickly.

Bamboo Tectonics, Made Legible

Bamboo is easy to romanticise and hard to build with well. Here the joints are not hidden. Steel clamps grip round rafters beneath a translucent roof sheet, and on the underside of the curved roof you can follow bamboo poles, plywood decking and even the metal conduit. That last detail matters. A designer who exposes the services alongside the structure is confident that the assembly can bear scrutiny.

Elsewhere, vertical bamboo slats sit between speckled stone piers under a bamboo-framed eave. This is a quieter use of the material, more screen than frame. Read together, these moments show that bamboo is doing several jobs in the project: structure, enclosure, filter and finish. It is not simply a cladding applied for atmosphere.

Washing in the Open

The interiors avoid the usual sealed, fan-ventilated room. In one restroom, a curved white tile wall carries round mirrors beneath a slatted bamboo ceiling, and white columns open the space directly to the forest. In another, stone basins stand in an open washing area under a curved timber roof, with the wooded hillside in full view.

White tile is a pragmatic choice for spaces that need hard cleaning, and the architects let it stay plainly utilitarian. The bamboo ceiling softens the room overhead without asking the walls to pretend to be something they are not. It is a sensible division of labour: durable surfaces where hands and water meet, and warmer material where the eye wanders.

Thresholds, Courtyards and Screens

Privacy in a public toilet is usually achieved with blank walls. Here it is negotiated through layers. One entrance is screened by woven rattan panels on bamboo rails set between stone piers, while a curling bamboo roof edge marks the doorway above the white tile. In another location, a translucent canopy on slender timber supports covers a courtyard with stone benches and a low river-stone wall.

These spaces suggest that the restroom stop is also a resting stop. A bench under filtered light gives hikers a reason to linger, and the building becomes part of the trail experience rather than an interruption to it.

Plans and Drawings

The site plans make the four-strategy approach explicit. One scheme arranges four enclosed volumes, for toilets, handwashing and storage, inside a circular paved court. Two other sheets include small before, demolition and after diagrams. This is a refreshingly honest way to document renovation: you can see exactly what was kept, what was removed and what was added.

The elevations and sections show how far the roof forms vary from site to site. They include a domed, lens-shaped roof on slender columns, a bamboo lattice spanning two restroom blocks over a central walkway, and a sloped bamboo frame over the men's room, storage and washbasin, with planted bamboo alongside.

The remaining drawings complete the range. One section shows a wave-shaped ceiling above a curved handwashing counter. Another sheet describes a flat roof of repeating bamboo panels over a wall with four round openings. A third shows a low pavilion with a slatted roof on spaced posts.

The detail sheets are where the project earns its credibility. They show beam, column and diagonal rod connections with steel sleeves and bolts, a bamboo purlin connection, and a bamboo mesh joint meeting a concrete wall. The wave ceiling even integrates an LED strip. Structural consultant Jian-Min Li Structural Design and contractor DCH Construction clearly had to resolve bamboo as a building system, not as a craft gesture.

Why This Project Matters

Forest agencies everywhere manage scattered, ageing amenity buildings on limited budgets. The usual response is either neglect or a catalogue product dropped from a truck. Basianshan offers a third option. You audit each existing facility and decide whether it needs a new building, a renovation, a new interior or just a roof. Then you tie the results together with one locally sourced material and a consistent level of detailing.

The bamboo is the visible story, but the transferable lesson is in the procurement and design thinking. Using domestically grown bamboo supports a local supply chain. Matching the level of intervention to each site avoids demolishing what can be kept. Treating a restroom as a shelter worth sitting in raises the bar for the most overlooked type of public architecture. We would like to see more park authorities take that seriously.

Basianshan Natural Public Toilet by Protoplain Architects (lead architect Yu-Hsin Yeh), Taichung, Taiwan. Area: 362 m². Completed: 2024. Photography: Rex Chu.

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