Østensjø school is situated in the Østensjø district at the northern end of Østensjø lake and it has 2 old listed school buildings and 1 school building that was built in 2012. The capacity shall be expanded from a B2 school to a B3 school with a parallel class by constructing 2 new school buildings with 3 floors on the school site, with a total area of 3955 m2 gross.
1 of the buildings, the 'west building' is situated on a slope by Østensjøveien. The building includes 3 home areas with the accompanying teacher workplaces and premises for an activity school for the youngest years. The 'north building' has 3 floors and is on the site´s north side by Fugleliveien, it includes a gym hall with the accompanying changing rooms and teaching rooms for music, science and art.