INSULATING EXTENSIONS

Part of the appeal of extending your home is the opportunity it affords to boost comfort levels. To ensure your newly enlarged living space will keep you nice and toasty in winter and pleasantly cool in summer, the extension’s outer defences will need to be fortified against everything the climate can throw at them. This means picking the right type of insulation for each part of the structure. The trouble is, once you start researching this subject it’s all too easy to find yourself bogged down with competing manufacturers’ claims couched in baffling techno-babble. So, what should you know?

Complying with Building Regs

Getting your extension to comply with heat loss targets, set out in the Building Regulations, is one of the key hurdles at the design stage. Fortunately this is a lot easier with new construction where you have the luxury of a blank canvas without all the upheaval of ‘retrofitting’ existing homes. So it makes sense to aim a little higher and try to exceed the minimum stipulated heat loss targets prescribed by the Regs, and reap future savings with smaller heating bills.

Another reason for ‘super insulating’ your new extension is that it can help get round the limits on the maximum amount of glazing that’s permitted (normally equivalent to 25% of the new extension’s floor area). With extra insulation in your walls, roof and floor it should be possible to compensate for increased heat lost through larger expanses of glass.

The Building Regs (Part L1B) set minimum heat loss K is better than 0.30W/m K.