Architectural practice BIG has completed the second phase of a project at Gammel Hellerup High School, Copenhagen, Denmark – the old high school of founding partner Bjarke Ingels.

The new addition, a 1,400sq m (15,069sq ft) arts and culture building, follows the completion of a multi-purpose sports hall in 2013, which paid homage to Ingels’ old maths teacher by using the mathematical formula for a ballistic arc – the flight path of a shuttlecock – to shape the geometry of its curved roof.

Located next to the sports hall, parts of the new two-storey building are beneath a football field. It features education facilities and classrooms for cultural activities covering arts, music, drama, and student counselling.

The phase one sports hall development was also underground, located beneath the school's courtyard.

BIG said the building had been designed to connect the sports areas with the gym’s existing educational facilities in one continuous flow. Students are able to walk through the sunken sports hall at the centre of the school’s courtyard to the classrooms, cafeteria, and out to the main entrance at street level.

The roof of the building extends the school’s existing football fields into a green carpet that can be used as informal seating to overlook sports events.

The new building complements the original sports hall by reversing materials and finishes. While the sports hall is made of concrete with wooden finishes, the new classrooms feature wooden walls spanning the length of the building, with concrete ceilings and floors.

Taken together, the two new buildings increase the capacity of the school in response to its growing popularity.