Curved Timber: 6 Times Architects Bent Wood to Their Will

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There are no perfectly straight lines in nature. Trees, with their rounded trunks and supple branches, are no exception but you wouldn’t know it by looking at most wood façades. The naturally sinuous qualities of wood are often lost as trees are milled into flat boards, to be used as cladding on rigidly rectilinear buildings. This collection, sourced from the Architizer database, features projects that take a different approach. These façades bend, twist and undulate to show us that architecture can be clad in wood without being so wooden.

That being said, creating curved wood façades is easier said than done. It’s a design challenge that requires clever detailing and close collaboration between architects, engineers, manufacturers, carpenters and, sometimes, even shipbuilders. Today, these diverse teams rely on a marriage of traditional craftsmanship and contemporary technologies, such as parametric modeling software and CNC milling machines, to create increasingly complex wood curvatures.

ONDA Restaurant by ALLIANCE ARKITEKTER, Oslo, Norway

Wood siding by Kebony

ONDA, the Spanish word for wave, is a fitting title for this seaside restaurant, located on Oslo’s Aker Brygge pier. Inspired by the movement of the water, the ribbon-like façade of glass and wood wraps around the building, framing views of the harbor and defining an undulating public space. The building’s organic form and sustainable wood cladding reflect the restaurant’s commitment to creating an all-natural dining experience. Both the façade and the surrounding deck are clad in Kebony, a wood product created by impregnating FSC-certified pine with furfuryl alcohol.

The alcohol, which is produced from a bio-based liquid, hardens the cell structure of the wood, creating a durable and maintenance-free finish without the need for oils or chemical treatments. As the Kebony ages it will naturally develop a silver patina, which is characteristic of many waterfront structures in Norway. In the architects’ words, the curved wood façade will “stand as an expression of our time and a proud reminder of our maritime traditions.”

Façade section and cladding details of Kamppi Chapel, image via ArchDaily

Kamppi Chapel by K2S, Helsinki, Finland

Kamppi Chapel, also known as The Chapel of Silence, sits like a large wooden bowl in Helskinki’s Narinkka Square. According to the architects, the building’s gentle curve directs visitors into the space while the wood cladding “shields them from the bustling city life outside.” To construct this rounded form, K2S turned to Finnish shipbuilders, Late-Rakenteet Oy, who produced a structure of tapered glulam ribs, and to the carpenters of Puupalvelu Rajala Oy, who milled the lumber for the project using CNC technology.

The exterior is clad in 1 3/8-inch-thick boards of locally-sourced spruce, which are finger-jointed together and notched into the curved ribs. The spruce was treated with pigmented Biowax, which will protect the surface from water while allowing the wood to age naturally over time. On the interior, the walls are finished in slightly thicker planks of oiled alder. The ceiling appears to float above this space, held apart from the walls by a perimeter skylight, which bathes the curves in natural light.

Diagrams of Kilden’s structure and cladding, image via Architect Magazine

Kilden by ALA Architects, Kristiansand, Kingdom of Norway

Under one timber roof the Kilden Performing Arts Centre unites three entities: The Agder Theater Company, The Kristiansand Symphony Orchestra and The Opera Sør. The undulating façade, clad in locally-sourced oak, invokes both the surrounding water and the hulls of nearby ships. In fact, Risør Trebåtbyggeri, a Norweigian shipbuilder, supplied the oak boards and was heavily involved in the construction process, along with several other companies: Trebyggeriet and Blumer-Lehmann, who produced a series of curved glulam beams for the structure, and Design-to­-Production, who provided custom CNC-milling for the project.

Using digital modeling software, this team worked with the architects to devise a system wherein the oak cladding is notched into the glulam beams which, in turn, are supported by a steel frame. This complex structure continues, uninterrupted, into the interior of the building, where the oak becomes an acoustic ceiling for the foyer. Like a rising theater curtain, this warm and curvaceous canopy marks the transition from reality to fantasy. In contrast to the main façade, the sides of the building are clad in a sawtooth pattern of dark aluminum panels.

Cladding details of Interims Audimax, image via Baunetz Wissen

Interims Audimax by Deubzer König + Rimmel Architekten, Munich, Germany

This temporary lecture hall was built to accommodate a recent influx of students attending The Technical University of Munich. With a shoestring budget and a nine-month construction deadline, the architects opted for a simple, wood-framed structure, clad in rough-sawn spruce. All of the lumber for the project was supplied and installed by the carpenters of Merkle GmbH. This boxy construction is enlivened by the cladding’s irregular substructure, which causes the façade to ripple.

The spruce, although stained black to obscure its aging, appears silver as the light reflects off its curves. In contrast to the dark exterior, the interior is finished in untreated oriented strand boards, a subtle reminder of the building’s impermanence. Deubzer König + Rimmel Architekten’s design was the winning proposal in an open competition held by the university. The jury presiding over the contest lauded the project in a statement which concluded: “This dark solitaire is a wooden building through and through. With its modulated shell, it shows new ways of using the sustainable building material — miles away from the cliché of the natural façade.”

Diagram of The 2012 Olympic Velodrome’s structure, image via Trada

London 2012 Olympic Velodrome by Hopkins Architects, London, United Kingdom

Wood Siding by Wood Newton

The Velodrome, a cycling stadium built for The 2012 Summer Olympic and Paralympic Games, rises in London’s Olympic Park like a great swell of timber. The elliptic façade, inspired by the wooden bicycle track at the center of the stadium, is clad in western red cedar, manufactured by timber specialist Wood Newton. A protective coating of Textrol oil enhances the cedar’s natural color and grain.

The ends of the boards are capped by aluminum fins, segmenting them into bays which better articulate the building’s curves. The cladding system features custom routed slots through which air can pass, allowing the entire stadium to be ventilated without mechanical means. Wood Newton also produced the timber cassette panels which make up the stadium’s double curved roof. These cassettes are supported by a steel cable net structure and finished in Kalzip standing-seam aluminum panels.

One North by Holst Architecture, Portland, Ore., United States

Wood siding supplied by Wetset Enterprises and Kaster’s Kustom Cutting

The curved wood design of One North breaks the mold of commercial developments in more ways than one. The architects employed a number of sustainable strategies, such as photovoltaic roof panels, super-insulated building envelopes and curved shading apertures, to ensure that the project was up to 60% more energy efficient than a typical office development. The buildings are framed in heavy timber and the façade’s curves are made possible by cold-formed steel assemblies, produced by RadiusTrack.

The use of sustainable materials was a top priority for the architects and builders, who became intimately involved in the selection and production of the exterior cedar cladding. All of the planks were responsibly harvested, logged and milled by two local timber companies: Wetset Enterprises, which provided the bulk of the cedar, and Kaster’s Kustom Cutting, which supplemented the supply when necessary. The cedar was finished with two coats of TimberPro stain and a fire-retardant treatment, as required by local codes. You can learn more about the construction of these beautiful offices in the video above, produced by the project’s contractors.

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