Marko Huttunen

Finland has a rich tradition of rural wooden churches, the most iconic of which grace the coastal plains like cubist sculptures, their steep gable roofs standing in defiance of the harsh northern climate. But for the Kamppi Chapel of Silence in downtown Helsinki, local firm K2S Architects turned tradition on its head, eschewing angles for curves in its ovoid bowl design.

K2S explored several forms for the Kamppi chapelEvolution of project massing

Though the roughly 38-foot-tall form is more suited for concrete, K2S made it work with the traditional, warm, familiar wood by utilizing clever detailing, computer-aided design, CNC milling, and a construction team that counted a former shipbuilding company—Late-Rakenteet Oy in western Finland—among its crew.

Steel brackets attach more than two-dozen curved and tapered ribs—CNC-milled glulam columns, each approximately 36 feet tall—to the concrete foundation. Steel brackets also anchor the glulam roof beams, the longest of which spans 49 feet.

Floor plan
Courtesy K2S Architects Floor plan

Once the structural frame was in place, local contractor Pakrak Oy added mineral wool insulation, sheathing, and a vapor barrier to the wall. Vertical furring strips with custom-designed, CNC-milled notches guided each plank of curved, finger-jointed spruce cladding into place. The notches are slightly angled, like teeth in a saw, to compensate for the wall’s pitch.

All of the lumber used in the chapel—glulam structural beams, exterior finger-jointed spruce planks, and interior alder siding—was sourced and processed within 125 miles of the site in the bustling Narinkka Square. The chapel was completed in May 2012 after 14 months of construction.

Building model, aerial view
Courtesy K2S Architects Building model, aerial view
Building model, aerial view of interior
Courtesy K2S Architects Building model, aerial view of interior
Indirect light spills down the double-curved walls, which are fashioned from oiled alder planks glued together to form one large wooden bowl. The 4¾-inch-by-1¾-inch alder planks were CNC–milled into 7,500 distinct shapes. The structure floats on a concrete foundation, allowing for thermal movement.
Tuomas Uusheimo Indirect light spills down the double-curved walls, which are fashioned from oiled alder planks glued together to form one large wooden bowl. The 4¾-inch-by-1¾-inch alder planks were CNC–milled into 7,500 distinct shapes. The structure floats on a concrete foundation, allowing for thermal movement.
The approximately 38-foot-tall, 2,900-square-foot Kamppi Chapel of Silence was built using traditional carpentry techniques and CAD-CAM technology, including CNC milling by the Helsinki-based Puupalvelu Rajala Oy. K2S collaborated with Finnish structural engineering firm Insinööritoimisto Vahanen Oy on the design. “We thought the chapel should have a strong independent identity to reflect the contrast between its spiritual function in a commercial city,” says K2S partner Mikko Summanen.
Courtesy K2S Architects The approximately 38-foot-tall, 2,900-square-foot Kamppi Chapel of Silence was built using traditional carpentry techniques and CAD-CAM technology, including CNC milling by the Helsinki-based Puupalvelu Rajala Oy. K2S collaborated with Finnish structural engineering firm Insinööritoimisto Vahanen Oy on the design. “We thought the chapel should have a strong independent identity to reflect the contrast between its spiritual function in a commercial city,” says K2S partner Mikko Summanen.
Curved, sawn-to-order 2-inch-by-1-3/8-inch finger-jointed spruce planks clad the façade. Once installed, the exterior wood was treated with Teknos Biowax, a pigmented, transparent nanotech wax developed by a Finnish company (it is not yet commercially available). The wax particles penetrate the wood’s cell structure deeper than conventional sealants and help repel water. After two years of exposure to the elements, the siding on the chapel has shown no change in appearance, the designers say. They anticipate a natural patina to form over time, but they expect to reapply the Biowax within 10 years.
Courtesy K2S Architects Curved, sawn-to-order 2-inch-by-1-3/8-inch finger-jointed spruce planks clad the façade. Once installed, the exterior wood was treated with Teknos Biowax, a pigmented, transparent nanotech wax developed by a Finnish company (it is not yet commercially available). The wax particles penetrate the wood’s cell structure deeper than conventional sealants and help repel water. After two years of exposure to the elements, the siding on the chapel has shown no change in appearance, the designers say. They anticipate a natural patina to form over time, but they expect to reapply the Biowax within 10 years.