Window design

● Choose the appropriate size of windows for the orientation and climate. Large windows on the north side of the home will maximise nat- ural heating. But large windows on the south side may cause heat loss.

 

● Wooden frames are attractive, provide good insulation and are eco-friendly if the timber comes from a renewable source. But bear in mind that they can be expensive to buy, especially if custom-made, and require periodical maintenance to ensure the wood does not rot. They are also hard to seal becausethe wood swells and contracts with changes in temperature.

 

● PVC frames are durable, require little maintenance and provide good insulation, but they are made from non-renewable resources and their production is a source of pollution.

 

● Aluminium frames are lightweight and durable. But because aluminium is a good conductor of heat, they can become hot to touch and also require some kind of insulation (a ‘thermal break’) or treatment to make them energy-efficient. In addi- tion, the production of aluminium uses large amounts of energy.

 

● Make windows taller rather than wider.This will let more light in.

 

● Select appropriate glass for your climate. Some types are absorbent,meaning that they allow heat into the house; others are reflective, meaning that they keep heat out.

 

● Consider double-glazing for cold areas. It’s expensive to install, but can cut heat loss by as much as 50 per cent. It can also help block outside noise.

 

● In warm areas, consider fitting insect screens over windows so that you can leave windows open and let cooling breezes in.

 

● Louvres, either in the form of louvred glass panels or louvred shutters, are a useful feature for warm climates, allowing you to admit and direct cooling breezes.