Tammisto Electricity Substation
Kivinen Rusanen Architects modernised a key power grid hub with a new building featuring four masonry patterns.
Located in Vantaa, the Tammisto Electricity Substation has served the Helsinki metropolitan area for decades. To enhance reliability, capacity, and safety, Fingrid Oyj constructed a new building for a 110 kV Gas-Insulated Switchgear (GIS) system, replacing the old air-insulated switchyard.
The project included new powerline structures, fences, a backup generator, extensive landscaping and greenery. Construction was phased to minimize disruption and ensure a smooth transition. It also allows for future expansion, accommodating growing electricity demands.
Architecturally, the project aimed for a cohesive appearance, adhering to Vantaa City's town plan regulations. The new building's design integrates with the historic substation and nearby residential area, featuring water-struck brick facades in warm tones and textures.
The site, near major transportation routes, commercial areas, residential neighborhoods, and Helsinki airport, is enclosed with a fence and controlled gate. It includes various buildings, the oldest being the Aarne Ervi-designed substation from 1947, now an office and protected by zoning regulations. Other facilities include a 400 kV switchgear building, transformer bunkers, open switchyards, and power transmission structures, surrounded by tall trees and forest patches.
The new substation building connects with the old one through scale, massing, and materials. Inspired by the old substation's two-part composition, the new building features triangular cuts, dividing it into three sections. The ends provide access and control facilities, while the long center section houses the main equipment and cable rooms. The two-story layout places serving spaces on the ground floor and the main GIS and control rooms on the second floor, with a machine room above.
The facades use water-struck bricks in four masonry patterns, highlighting the structure. Thirteen types of custom bricks were used, produced from detailed 3D models. The building's frame is prefabricated concrete, with double-skin facades supported by a steel frame.
Natural light enters the south and north sections through double-skin walls of lattice masonry, offset from full-height glass curtain walls. The center section is windowless, but equipment rooms receive indirect light. Lattice masonry ensures safety and prevents direct visibility into the substation.
The project also improved two 1980s concrete transformer bunkers with Umbra colour patination, giving the site a unified warm outlook with reddish bricks, Cor-Ten steel, and Umbra-treated concrete.
Located on the western edge of the site, the new building allowed the existing switchyard and power lines to remain operational during construction. Once technical installations were complete, the old switchgear and power line structures were removed.
The Tammisto Electricity Substation project by Kivinen Rusanen Architects enhances sustainable urban infrastructure, supports electrification, provides reliable power, and improves the aesthetic and cultural integrity of the site and surrounding landscape.
Photography: Max Plunger, Tuomas Kivinen
Awards: Architecture MasterPrize 2023: Winner / ICONIC Awards 2023: Innovative Architecture, Winner
