Design tips for the hot humid climate

Because the humidity is high, air movement is crucial, to help perspiration to evaporate.

We need: -

• Windows opposite each other to allow cross-ventilation;
• Long, narrow floor-plan in sleeping zone, to maximise through ventilation in bedrooms;
• Open-plan living areas with high ceilings, to maximise air movement and reduce radiant heat to occupants (see our example house plan

• Choose window type for good airflow eg, louvres rather than awning/hopper windows;
• Elevate house to catch the breezes (in areas prone to tropical cyclones, there is a trade-off - construction cost increases);

• Extra ventilation from ceiling fans, rotary vents and wind traps will be a bonus;

• Boundary fences should not block airflow (a low cyclone-wire fence is preferable to a high brick wall;
• Make sure that your garden layout hasn't blocked the summer breezes;
• In a new subdivision, the spacing of buildings should be carefully considered to avoid obstruction of the wind;
• Air movement means that mosquitoes and sandflies will be less likely to linger around the house - they prefer still air.

Because the night-to-day temperature swing is rather small:

• materials with heat-storage capacity such as bricks and concrete are of little benefit, particularly for bedrooms - a lighter house construction (timber, fibro) will cool quicker at night;

Because the climate is warm all year, building heat gain should be minimised by:

• orienting the long axis of the house east-west (if you cannot orient for cross-ventilation, see our Darwin case study). The long north- and south-facing walls can easily be shaded by the eaves;
• keeping windows on east and west walls to a minimum;
• shading the walls and windows - use shutters, verandahs, canopies and/or eaves and fixed overhangs;
• using pale colours for walls and roof, to reflect the heat of the sun;
• reflective foil insulation is good, because it reflects incoming sunshine, but bulk insulation is not desirable, because it prevents the house cooling down at night;
• ventilation of the roof space, to reduce heat build-up there: the increased heat loss in the cooler season is not important;
• metal roofs which cool rapidly at night. Daytime heat gain can be minimised by using sheeting with a reflective coating on its underside.

Because of the warm climate:

• outdoor living areas( verandahs or under an elevated house ) will be particularly useful. Shelter from the rain is needed in summer; shade is also desirable.

If you decide to air-condition some or part of your house:

• the air-conditioned part of your house needs bulk insulation;
• drafts should be blocked in this section;
• double-glazed windows may also be cost-effective

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