Allen Jack+Cottier adopted an imaginative approach to materials, structure and form when designing this multi-purpose hall on Milson Island in the Hawkesbury River, NSW. Milson Island is a holiday camp, totally focused on health and social equity, which groups of disadvantaged youths visit on week long trips. The brief was to deliver a robust multi-purpose sports hall to be used for indoor sports such as basketball, netball and volleyball, as well as theatre, dance performances and exhibitions. But its real purpose is to allow anyone who comes to this place to participate and have lots of fun while doing it, regardless of their physical or mental capabilities.
A careful study of local conditions resulted in a building that fits gracefully into its extraordinary natural context. Its curving lightweight canopy seemingly floats over the landscape of its beautiful island site. The curved form of the building is an overt and direct expression of its thermodynamic analysis. A combination of twelve wind turbines and a series of floor mounted louvres ensure the building remains cool in Sydney's fierce summer heat, and when closed in winter act like an insulation blanket. The design exploits the inherent properties of plywood - the shape of the building is designed to unload wind forces on this exposed site, thus reducing the weight of the structure by 30%.
There are no visible ridges, eaves, gutters, downpipes or skylights on the exterior. The continuous wall/roof shape dispenses with gutters, reducing maintenance and removing a major bush-fire hazard. The use of natural thermal ventilation generated the roof shape, as smooth airflow required a clean, crisp interior skin. Rainwater, free from the blockage of leaves, falls directly into rock gardens for filtering and collection. Natural light entering through extensive glazing creates an almost art gallery-like feel to the hall. This is a powerful building which in its frugality demonstrates the essence of shelter.