Architecture collective Badweather has transformed a 17-metre canal boat into Soak, an off-grid bathhouse that moves to a new location along London's waterways every two weeks.

Soak combines a wood-fired sauna, two cold plunge pools, showers, changing facilities and a small bar for up to 12 people.

It operates without mains water, electricity or sewage connections, instead drawing water directly from the canal and passing it through a six-stage filtration and UV treatment system before it is used for bathing.

Electricity is generated by solar panels and stored in an onboard battery system, while a wood-fired stove provides heat for the sauna.

The project was developed by Badweather co-founder Leo Sixsmith and chef and former restaurateur Riccardo Codacci-Pisanelli, who wanted to create a communal bathing space that could move through the city rather than occupy a permanent site.

"The changing location of the boat means that the view through these windows is never the same," Sixsmith told Dezeen.

Soak began with a near-derelict 20-year-old canal boat, with rotten floors, water damage and a steel hull that required extensive restoration. Around 40 people worked on its conversion, with the existing hull dictating much of the interior layout.

The exterior was painted cream with black and red detailing, while circular portholes puncture the sides of the boat.

Inside, the original 11-inch openings have been enlarged to 18 and 32 inches, with fiery-red frames that make the windows stand out against the hull.

At the bow, a large picture window replaces an original steel door, opening the narrow interior towards the water.

The interior follows the boat's long, narrow form. Visitors enter through a dark changing and reception area lined with stained marine plywood. They then pass into a brighter plunge and shower room, featuring pale green tiles, stainless-steel pools and a central skylight that brings daylight into the boat.

"The wet room is intentionally kept completely free of timber," Sixsmith said. "Its harder, clinical finish allows for easier maintenance, while heightening the sensory contrast with the warmth of the sauna."

At the bow, the sauna is lined with thermally treated Aspen and Alder wood and is centred around a wood-burning stove.

Two benches were suspended from aluminium beams rather than supported by legs, allowing them to overlap within the tapered hull.

The boat's cramped dimensions were a major constraint, but Badweather aimed to use them to shape the interior. "Every centimetre had to work exceptionally hard," Sixsmith said.

Founded in London in 2019 by Oli Brenner, Sophie Mei Birkin and Sixsmith, Badweather is an experimental architecture, scenography and design collective working across installations, objects, lighting and buildings.

Its previous work includes temporary structures for nightclubs and festivals, including the ongoing Pipeline project, a floating communal hearth made from reused corrugated polycarbonate.

Other bathhouses featured on Dezeen include a communal sauna and hydrotherapy bathhouse in Montreal and the turquoise-tiled Komaeyu public bathhouse in the suburbs of Tokyo.

The photography is by Kaye Song.