The successful design of naturally ventilated public spaces requires the careful positioning of ventilation openings within the external building envelope or internal building structure to ensure comfortable year round operation and minimisation of cold draughts in winter. Some factors directly influencing internal environmental conditions include external ambient temperature, local wind speed and direction, location and size of ventilation openings, height and orientation of structure as well as building, solar and internal gains.

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When a large atrium street forming a key focal entry point into a new district hospital development suffers from acute summer overheating then careful investigation is needed to establish the facts and bring the situation back under control. In this case a clear inflatable flexible membrane roof structure provided very little solar shading and the resultant high level heat build-up was exacerbated by artificial restrictions imposed on use of both high and low level natural ventilation openings within the atrium street during warmer weather.

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Collective design team responsibility was acknowledged with improved temperature monitoring and anticipatory control methods used to limit heat build-up over extended periods of warm weather by the building operator. A subsequent design briefing note was prepared identifying control limitations inherent with use of natural ventilation when the internal environment develops into more than just a transient public space.