The project was commisioned by the Municipality of Tønder featuring a 3.000 m2 extension to the existing facilities. Danish architecture office SLETH led by Søren Leth and Rasmus Therkildsen were chosen as winners of an open design competition. The building is an extension and renovation of the existing town hall of Tønder originally designed by the icelandic architect Halldor Gunnløgsson.
SLETH's design focuses on preserving the qualities of the existing but making the extension a much more open and transparent working environment with clear references to the existing building in terms of window framings and the incorporation of the traditional red brickwork. It was crucial for the architects to make a strong linkage to the magnificent marshlands that surrounds the building making them both an integral part of the building interior while also respecting them on the exterior. This has been achieved primarily by pulling back the facades in a slight curve and reflecting the colours and shapes of the marshlands in the minimalist framings of the facade.