Grønnåsen School is located on a hill at the northern end of the island Tromsøya. The original building from 1968 is characterized by straight lines, white walls with continuous rows of windows and a flat roof. There are three storeys and the footprint has nothing but right angles. Its architects were clearly inspired by international modernism.

The school was extended in 2006 and got a new entrance lobby and canteen which is also used as a lecture theatre. The extensions' elevations are clad with brightly coloured panels with colours varying from one wall to the other.