by Heather Livingston
Contributing Editor

Summary: On June 22, Steven Holl Architects (SHA) was awarded two Royal Institute of British Architects (RIBA) International Awards for Architecture 2007, one for the New Residence at the Swiss Embassy in Washington, D.C. Commissioned by the Swiss Federal Office for Building and Logistics, the 25,000-square-foot building replaces the previous ambassador residence and was completed in September 2006.

Euro-American endeavor
Designed with Lucerne, Switzerland-based Rüssli Architekten A.G., the Holl team competed against nine other Swiss-American teams for the replacement of the Washington, D.C., residence of the Swiss ambassador. “Justin Rüssli used to work for Steven and then took over his father’s office in Lucerne,” says Project Architect Olaf Schmidt. “He was familiar with what Steven’s doing, so it was a good setup to split the work between the two offices.”

Schmidt notes that one of the interesting challenges during construction was the presence of two independent contractors. The general contractor was Washington, D.C.-based firm Davis Construction. The MEP work was completed by Swiss contractor AF Steffen Engineers. “The reason why we had it set up that way was that one, they couldn’t find any competitive bids for the kind of systems that they wanted in America, and then two, they were also thinking that they wouldn’t get the same quality as they would bringing in those people, so that was kind of challenging to have two essentially independent contractors working side by side and still having to coordinate between the two,” explains Schmidt.

A line diagonal
The residence is located on a hill in Northwest Washington with a direct view through the trees to the Washington Monument in the distance. “From the top of the hill you have this diagonal view, parallel to Connecticut Avenue, to the Washington Monument,” says Schmidt. “That’s a very distinct feature on the site. Steven incorporated that feature into the architecture in that he drew this diagonal line through the building and grouped a series of rectangular spaces along that diagonal axis.” The diagonal line of overlapping spaces drawn through a cruciform courtyard plan was the conceptual starting point. Schmidt says that the other key design concept was materiality. Holl created an analogy between the Swiss Alps, with their black rock covered in white snow, and the building as a black charcoal-stained concrete with sand-blasted structural glass planks.

A primary challenge to creating an ambassador’s residence is that it is a private house and a representative cultural gathering place on which standards and self-image of a country are measured. To meet the dual requirement, official arrival spaces and ceremony spaces are connected along Holl’s diagonal line on the first level, while private living quarters are located on the second floor. The ground floor features both grand and intimate dining rooms, three salons, the reception hall, and a commercial-grade kitchen that serves the public spaces. On the second floor, the ambassador’s 2,000-square-foot living quarters include the master bedroom, three additional bedrooms, living room with a terrace, kitchen, and study. Two additional suites for official guests of the embassy are on the second floor and feature both living rooms and bedrooms.

Sustainability is key
Sustainability was a key feature demanded by the client, says Schmidt. SHA incorporated a green roof that is planted with sedums to help retain storm water and lessen the heat island effect. The residence has a highly insulated building envelope to keep cooling and heating costs low, coupled with radiant heating and an efficient cooling system with mechanical equipment from Germany and Switzerland. Computer-controlled exterior shades minimize heat gain by automatically dropping when the interior temperature rises above a set degree. The floors are recycled glass terrazzo floors and rapidly renewable bamboo.

In announcing the 2007 RIBA International Awards for Architecture, the jury praised the new residence at the Swiss Embassy, saying that its “almost domestic scale of the plan and the external form of the building belie the grand scale of the interior spaces that reflect the building’s formal public function.” RIBA International Awards are given annually for buildings that have high architectural standards and make a substantial contribution to the local environment.