Whether you’re designing a new home or trying to keep cool in a finished house or flat, there are some common principles which can help keep us comfortable during extreme temperatures.
Block the sun from entering your home:
External blinds or shutters can have a huge impact on whether excess solar heat makes its way into the home, far more so than internal curtains or blinds. If you don’t have these, keep internal blinds or curtains drawn during the day. When choosing new windows, consider solar-control glass with a low g-value to reduce unwanted heat from the sun.
Keep the warm air outdoors:
If the temperature outside is higher than inside, keep windows shut during the hottest parts of the day to stop heat from flowing in.
Let the cool air in:
Open windows in the early morning, evening, and overnight to let cooler air in. For better airflow, open windows on opposite sides of the house to create a cross-breeze. In multi-storey homes, open windows both high and low to draw hot air out—this “chimney effect” can also be achieved by opening your loft hatch if you have one. Consider lockable louvres or grills if you need these in order to leave a window open securely. Windows in new homes where the whole frame and not just some panes are openable to the widest possible angle will provide much better ventilation, and perfom far better under the Building Regulations Part O.
Think about where your windows are:
Rooms with large windows heat up fastest. South-facing windows get the most sun in summer, while west and southwest facing windows receive strong afternoon and evening sunlight. East-facing windows catch the morning sun when temperatures are lower, posing less of an overheating risk. North-facing windows contribute the least to heat gain. Be mindful that roof windows may be exposed to direct sunlight for much of the day.
Plan for shade:
In the long run, architectural features like overhangs or neighbouring balconies can shade windows and avoid excessive solar gain. Planting trees or other greenery nearby can have a similar impact.
Insulate well:
It’s commonly misunderstood that homes which are great and retaining heat in winter will overheat in the summer. In fact, the opposite is true. Insulation works both ways, and a well insulated home will avoid gaining too much heat during a heat wave.
Reduce indoor heat sources:
Avoid using ovens or other heat-generating appliances during the warmest hours. When designing new homes, the location of ducts, pipes and services can also have an impact on temperatures.
