Stove

Saint-Gobain Architecture Competition

Team Work

Sustainable Housing and District Regeneration

Site: Viikki Campus, Helsinki, Finland

Area: 32000m²

2024.02-2024.04

Located in the Viikki district of Helsinki, the site is defined by snow cover and a strong natural landscape. The project concept centers on a thing that is both concrete and abstract: the hearth. It is a place for making fire—for warmth and cooking in everyday life—while also serving, in an abstract sense, as the core of shared domestic activities and a “reactor” that transforms natural resources into usable energy. In Helsinki, heat-related rituals such as sauna are especially important. Sauna culture is a key part of local life, yet current patterns of use can involve a degree of energy waste. This project therefore takes the reuse of sauna waste heat as its design driver—creating thermally comfortable shared residential spaces—while using this strategy to activate a responsible cycle of site biomass energy and building life-cycle operations.

At the district scale, the new buildings respond to the existing morphology and orient toward three different directions, producing three distinct curved interfaces and corresponding public-space characters. Together with the adapted existing buildings, their internal courtyards form an integrated heat-transfer system that captures sauna surplus heat to warm and insulate both housing and shared spaces. The renovated buildings also undergo façade upgrades to better regulate heat. To connect the new construction with the preserved and retrofitted structures, the landscape design uses the two curved building edges and the forest edge to shape a comfortable outdoor courtyard.

The project also proposes a coherent network of production and construction activities. Timber is sourced from the abundant local wood resources; excess biomass is burned for energy; materials salvaged from demolished on-site structures are reused; and wood waste generated during production is fed back into the heat source. When the buildings eventually reach the end of their life, the modular units can be disassembled and returned to the landscape—supporting birdwatching habitats or being reconfigured into new programs that serve the surrounding community.

Thermal Mass

The project studies the history of dwelling through thermal mass, focusing on how thermal mass interacts with different media and environments.

Biomass

The site’s western ecological zone contains rich biomass energy resources, the northern campus research area includes a thermal energy research center, and the southern hillside provides abundant timber—together establishing the foundation for a locally closed material cycle to support both new construction and retrofit.

Circulation of Pedestrian and Bikes — Three Curves and Three Zones

Thermal Section

Sauna waste heat is transported via piping to the courtyard, where it works with solar thermal radiation and an operable roof to regulate the temperature of shared spaces—achieving comfortable indoor conditions in winter. The heat is then radiated to each dwelling through hollow, double-layer conductive wall assemblies.

Hollow Wall between Sauna and Changing Room

Main Bedroom
Prefabricated Terrazzo Click-on Cladding

Living Room and Kitchen — Main Bedroom
Prefabricated Terrazzo Click-on Cladding

Landscape Strategy — Water and Heat Utilization

Renovation Building Function Zone Analysis

Afterheat From Sauna in Hollow Wall — Solar Radiation

Construction
Local, on-site construction supports a circular use of timber and biomass energy—for example, salvaging materials from partial demolition and old furniture, and processing wood waste into fuel for the sauna.

Demolition and Reuse — Construction
Local, on-site construction supports a circular use of timber and biomass energy—for example, salvaging materials from partial demolition and old furniture, and processing wood waste into fuel for the sauna.