The building's external envelope consists of solid walls with window openings (to the north and south) while to the west there are infill panels. Originally both columns and beams were exposed, but this was changed during renovation in 2006. The infill panels consist of aerated concrete blocks now clad with glass where there were previously varnished aluminium sheets. The windows are placed midway between the columns. A similar principle is applied to part of the recessed facade facing Kemnerbakken. Towards Vestregata runs a continuous canopy above the ground floor, which also shelters the main entrance. There are two small circular windows up at the top floor by the northwest corner. The circular window was a much loved feature of Norwegian functionalism (the Nordic term for early modernism), but maybe in this case they were just an acknowledging nod in the direction of the school's maritime connection.