Situated in a residential area in the heart of the city, the Brillantmont International School campus contains several heritage buildings, built between 1896 and 1928. The domain is also classified as a heritage garden. Locating a potential terrain for a much needed multi-purpose hall was far from evident; the new structure had to be inserted between the buildings and the protected trees. To preserve the existing quality of the site, the proposition was to build underground. The new underground facility is set into the slope maintaining the outdoor basketball court on it’s roof and preserving the park and lake views for all the buildings. The main hall is circumscribed by four volumes corresponding to four sections of the brief: a music room, a stage, a spectator’s gallery and a foyer. Natural light, the predominant theme of the project, is guided inside through four light-wells disposed at the cardinal axes. Through the skylights one can see the main buildings and hence find his bearings. The materials are basic and are not covered; retaining walls and other load-bearing elements are in standard reinforced concrete. The floors are in sanded down coloured cement. All metals are bronze coloured aluminium. A thick curtain in gold-covered silk transforms the sports hall into a theatre with a capacity of 350 sitting spectators.