The AA membrane canopy provides constant weather protection to the terrace. Yet it is so permeable that it maintains views of the surrounding London roofscape and avoids excessive wind pressure. Strong wind loads and the terrace’s low load-bearing capacity precluded a closed surface: the structure is supported by three existing columns, which are only capable to a small degree of resisting the horizontal loads resulting from torque moment. A system was developed, based on composite components, that reconciles the performance criteria – allowing light and air to enter, maintaining views and providing protection from the elements – by explicitly defining each component in an overall system.