Completed in 2008, the Flat Iron Building is an eco office developed by Skanska and designed by Rosenbergs Arkitekter. The precast concrete building forms a wedge between Torsgatan in central Stockholm and the rail depot of the main train station. Concrete was chosen due to the short construction time and its ability to form a solid mass. This doubles as both thermal mass to slow the transfer of hot and cold making the building more efficient and the mass also acts as a sound barrier between quiet residential buildings and the noisy train yard. With its proximity to the train station and the center of the city, the building has excellent transportation options for its employees.
The exterior is punctuated with large square windows with one pane flush with the exterior and then inside a double paned window creates a very efficient envelope that provides lots of natural daylight. A narrow footprint ensures that natural daylight reaches every room inside. A white, reflective roof minimizes urban heat island effect and the interior was designed to be flexible for changes in office staffing. Tenants are advised by Skanska on best materials in order to create a healthy and eco friendly interior. The building was awarded LEED Gold certification and Rosenbergs Arkitekter received the Concrete Industry Architecture Prize by the Norra Bantorget and was named third runner-up in the Stockholm Building Competition in 2008.
Images ©Åke E:Son Lindman, Tord Rikard Söderström