SAUNA

Löyly, a wooden rock structure built on the shore

Located on the shore of Hernesaari, Löyly does not look like a typical sauna. It does not mimic a cottage sauna, a log cabin, or an old neighborhood sauna, but instead stands as a low, angular building right by the water. Designed by Avanto Architects, the complex opened in 2016 on a former industrial and port area that Helsinki was developing into a new waterfront neighborhood.

The creation of Löyly was a multi-stage process. Initially, a temporary sauna village was planned for Hernesaari, but the idea proved not to be financially viable. After that, a floating sauna was developed. That, too, never came to fruition, because the waves and ice floes on the open sea would have made the structure too difficult to build. The final structure was not realized until the idea took shape as a free-form wooden complex anchored to the shore, and funding for the project was secured after Jasper Pääkkönen and Antero Vartia joined the effort.

The basic concept of the building is simple. The warm interior spaces, saunas, and restaurant are located in a dark, rectangular section surrounded by a large wooden shell. This shell is what makes Löyly recognizable. It shields sauna-goers from outside view but does not block the sea view from the inside. At the same time, it shades the large glass surfaces, protects the building from coastal weather, and forms steps, terraces, and cooling-off areas.

In Löyly’s design, the sauna experience is not confined to the steam room. The movement inherent in the sauna ritual—between hot and cool, indoors and outdoors, the benches and the sea—has been integrated into the architecture. You can walk on the wooden shell, sit on its landings, and its steps offer a view of the sea. The building is designed to be low enough that it does not block the views of future residential homes, and the graying of the wood has been allowed to become part of its character. Over time, the building is intended to blend into the hues of the coastal cliffs.

One of Löyly’s most distinctive features is its wooden exterior. It consists of approximately 4,000 unique wooden pieces, which were computer-cut and numbered prior to installation. The construction process was like putting together a jigsaw puzzle. Initially, an attempt was made to accelerate the graying of the wood pieces using iron sulfate, but this experiment was not included in the final design. The plan to oil the slats was also abandoned, as there were so many pieces that a single treatment cycle was estimated to take an unreasonably long time.

Löyly combines a public sauna, a restaurant, and a seaside urban space. It features wood-fired saunas, a smoke sauna, cooling-off areas, and the opportunity to swim in the sea. For international visitors, it offers an accessible way to experience the Finnish sauna year-round. For Helsinki residents, it introduced a new kind of public sauna at a time when traditional public saunas had become scarce and, for many, the sauna had shifted to a private space at home or at a summer cottage.

Löyly quickly became an internationally renowned architectural and sauna destination, but behind it lies a long series of discarded ideas, technical compromises, and experiments with materials. The finished building appears simple precisely because so many complex solutions are hidden within its wooden shell.