Building One of the Jubilee Wharf development is a fourstorey building with maisonettes on the upper two floors and workshops on the ground and first floors. Designed to be highly airtight (tested to 1.5 air changes per hour at 50 Pascals), the roof of the building is fitted with a series of wind cowls to provide fresh air without wasting valuable heat, particularly during cold weather. The wind cowls allow all the rooms in the maisonettes to be naturally ventilated, without the need for electric fans or complex controls.
The wind-cowl head is made of marine-grade aluminium with air-extract vent and air-supply intake at opposite ends. A contra-flow heat exchanger is set below the head so the extracted warm air heats fresh incoming air. Each room has a supply-outlet duct at low level and an extract duct at high level.
The ducts are housed at each party wall in an enclosure of timber studs lined with plasterboard. Due to the resistance of air in a lowpressure passive design, duct geometry is limited to two 45infinity turns on any duct run; the horizontal length after the second turn is limited to 300mm. These design parameters were considered early in the building layout to achieve the correct spatial design alongside the demanding ventilation parameters.