wooden boat sauna by sandellsandberg sails on stockholm archipelago

Designboom_ Gently sailing on the Stockholm Archipelago, Big Branzino is a boat sauna with a captain on its bow. Designed by Thomas Sandell and Johan Strandlund from the Swedish architecture firm sandellsandberg Arkitekter, the floating cabin can voyage at a speed of five knots (roughly 9km/h), offering an intimate space for relaxation and detox.

The design duo opted for clean silhouettes and simple, honest materials, making wood the protagonist of the project. Clothed in rugged pine, the exterior blends into its natural setting, while the curved shapes that outline the openings reflect the shoreline formations. Guests are invited to enjoy the hot steam while sailing, as well as to unwind and indulge in nature.

Standing on top of a catamaran steel hull, Big Branzino emerges as a timber structure hand-built by master carpenter Leif Persson. The steel hull provides the needed stability as well as storage space, allowing the interior to be minimalistic and breezy. Walls and furniture are made of western red cedar due to its great characteristics for sauna and outdoor use. A wooden ladder guides visitors to the upper floor — a recessed roof terrace featuring a foldable cedar table that can be stowed away when the occasion calls for dancing or sunbathing.

‘The design revolves around its distinct shape, where the bow shape is the central theme throughout. The lowest point of the arch creates warmth and closeness to the glow of the fire, and as the arch rises to the sides, it allows the stars of the night sky to be admired from the inside,’explained the architects.

At the heart of the vessel is the sauna oven, which oozes with tones of intimacy and comfort. The interior is defined by transparency thanks to a generous amount of glazing that maximizes natural light and scenic views. This allows the glow of the fire to light up the space and to be seen from the outside. To achieve glass in all directions, the framing was custom designed in close collaboration with the blacksmith.

All steering and navigation equipment is concentrated on top of a cedar cabinet on the bow deck. To provide a fully immersive experience, sandellsandberg Arkitekter opted for a revolving brass case to conceal all modern navigation tools while adding a delicate aesthetic. When the sun goes down, the roof terrace is subtly lit by a concealed LED light along the wall top, allowing uninterrupted views of the night sky and the great views of the surrounding archipelago.