We have had a bit of an up and down summer weatherwise, but Auckland usually puts on a bit of a heatwave late in February and early March, so we still want a cool and comfortable house for those warmer months, so it is important to consider some ideas for designing ‘cool’ buildings, i.e. those that aren’t too hot during the summer months. As Amy Hendry of Four Walls Architecture elucidates, “We design to trap warmth in winter, but how do we design for cool in summer months?” Amy goes on to clarify three rules for summer comfort: good insulation to trap heat out (the opposite of winter!), exterior shading to keep sun out, and good cross ventilation for cool airflow through the house.
During the summer heat ventilation is necessary in buildings to remove ‘stale’ air and replace it with ‘fresh’ air, helping to moderate internal temperatures, reducing the accumulation of moisture, odours and other gases that can build up during occupied periods, and creating air movement which improves the comfort of occupants.
Similarly, external shading will help to counter the heat of the sun and so help to keep a building cool. Providing shade over building openings and outdoor spaces can reduce temperatures and save energy. There are many options for external shade, and to be effective, external shading must be considered, along with other passive design features such as location, orientation and layout, and window size and placement.
Verandas and pergolas provide excellent shade, and deep verandas are particularly good for shading east and west facing elevations although they will still admit very low angle sun. They can be used in combination with planting or screens to filter sun, and pergolas covered with deciduous vines provide very good seasonal shading
A well-insulated and well-designed home provides year-round comfort, cutting cooling and heating bills by up to half. This, in turn, reduces greenhouse gas emissions. Stay cool inside this summer by going to Four Walls Architecture’s web page at http://www.fourwallsarchitecture.co.nz .