The extension consists of a four-storey angular building placed along Amaliegade and facing a courtyard along the southern property line.
Part of the extension has the same the height as the original headquarters whilst the opposite part, ie the Amaliegade facade, matches the height of the adjacent building housing the Ministry of Energy. A low glass building connects the angular building and the existing headquarters.
The new buildings and the existing canteen terrace surround a grass-covered courtyard. The line between the courtyard and the terrace is marked by roof lights fitted in a plinth above two auditoriums. Office areas allow for flexible office landscapes.
The facades are covered with light natural Gotland stone, whilst windows are made of sand-blasted aluminium with glass in a neutral grey colour. Inside surfaces are light wooden panels, painted walls and floors in grey colours. Partition walls in offices are flexible, made of glass, wood and aluminium matching the colours in the rest of the building.