Fingrid Hepokorpi Substation
The Hepokorpi electrical substation in Espoo, completed in 2025 by the transmission system operator Fingrid, is a pioneer in the modern construction of critical infrastructure. Nordtreat provided the fire protection for the glulam and CLT structures of the concrete-and-mass-timber substation building, achieving the required fire classification of B-s1, d0.
The Hepokorpi electrical substation is a unique project where mass timber architecture supports the core goals of advancing the green transition, enabling zero-emission energy production, as well as helping the City of Espoo in reaching its carbon neutrality goals. The project was designed by Kivinen Rusanen Architects Oy, with RTA-Yhtiöt Oy as the main contractor.
Basic information
- Type of Building:
Electricity substation - Fire protection class:
B-s1,d0 - Fire protected:
CLT & Glulam structures - Location:
Espoo, Finland
Beautiful wooden architecture inside the large substation
The architectural design had to meet high standards to ensure swift permitting under a tight schedule. The large building sits adjacent to a busy highway, nestled between forest and built environment.
Architect SAFA Tuomas Kivinen explains that the double façade features uniquely colored ceramic panels, with the façade composition reflecting the forested slope site’s topography and color palette. For the first time in Finland, the main equipment halls of the substation were constructed using mass timber. The building's support structures were cast on site from concrete, while steel landscape pillars were designed for the exterior.
