Wind tunnel modelling provides an accurate and definitive assessment of wind conditions prevailing in the surrounding streetscapes and any critical out-door areas within or adjacent to the site. Wind velocities are measured in the wind tunnel and are related directly to comfort criteria. If any treatments are required, this study will also enable the testing of the effectiveness of these treatments to ensure their effectiveness. When required, innovative and cost-effective solutions to potential problems are to ensure that the architects’ design intent is achieved. WINDTECH Consultants utilises hot-wire anemometry, which is the most accurate technique available.

If required, a frequency analysis can be undertaken for wind environment studies to determine the approximate number of days in the year where the wind speeds are expected to exceed given criteria.

This medium-rise residential development, consisting of two buildings, is located in one of Sydney;s city fringe suburbs. Initial testing without the effect of the proposed landscaping showed that wind conditions near some of the building corners and near the gaps between the two exceed the criteria for comfortable walking. The model was modified to incorporate strategic planting, which was tested in the wind tunnel. The retesting showed that a refinement of the initial planting regime was sufficient to bring the wind conditions in most areas to within the relevant criteria for the respective areas. However, the strategic tree planting approach was insufficient for the proposed outdoor dining area, located at the corner of an undercroft area. The best that could be achieved with strategic planting at that area was to bring the wind conditions to within the safety limit. Furthermore, the criterion becomes more stringent as this area involves stationary activities. The introduction of a freestanding canopy (refer to the image) to deflect the sidestreamed winds so as to satisfy the relevant criterion.

Example of a solution to a sidestream effect affecting a proposed
outdoor dining area: Addition of a free-standing canopy at the corner of the undercroft area to deflect downwashed side-streams and introduce street tree planting for protection from incident ground level winds.