Tammisto Electricity Substation by Kivinen Rusanen Architects

The Tammisto Electricity Substation is a crucial hub for power transmission in the Helsinki region. Its renewal involved replacing an outdated, extensive switchyard with a new 110 kV Gas-Insulated Switchgear in a new building. Extensive landscaping was added, partly in place of the demolished old switchyard structures, enhancing the site aesthetics and aiding rainwater runoff management. The architectural goal was to create a harmonious visual language for the site’s new and old structures.

The massing, roof form, and façade materials reference an existing, historic substation on the site. At the gable ends, the interior receives natural light through double-skin walls of perforated masonry, offset from full-height glass curtain walls. Four different masonry patterns distinguish the various interior spaces and functions behind the facades. The facades of the two concrete transformer bunkers were treated with Umbra color patination. The patina’s reagents penetrate the surface of the concrete, where they react with the cement to form reddish-brown colored compounds.