Insulation by-law on all new homes

Press, 13 April 1978, Page 10

Insulation by-law on all new homes

The Standards Association has amended its model building by-law to require a reasonable level of insulation in all new homes. Local authorities are expected to adopt this amendment in line with Government policy as stated in the 1977 Budget and several ministerial statements.

The straightforward bylaw requirement is accompanied by two “means of compliance” standards. One sets out the actual thermal resistances (a scientific meaure of how much heat can be lost) that are required. The other sets out methods of measuring or calculating the thermal reistance of any type of wall, roof or floor.

Many responsible manufacturers have already had

tests made on their products so that builders and designers will know precisely what contribution they will make to the total thermal resistance of a home. Others are 'in the process of having such tests made.

The actual thermal resistance levels required have been expressed in scientific measurements and not as a single requirement to use so many millimetres of such and such. This is because the Standards Association was determined not to restrict individual choice unnecessarily, and not to prevent design innovation. For the same reason, it provides a range of choices — higher thermal 'resistance in the wall means you need less in the roof, and so on. In addition, it recognises that it is very much easier to improve the thermal resistance for most types of building than for a few special types, and allowance is made for this on an interim basis. In all cases, the levels have been chosen to allow a profit for the homeowner: an insulated building means he is able to save more on power bills than he originally spent on insulation. (As prices change, future amendments may be necessary to keep costs in balance). The by-law has been kept as simple as possible. The average house-builder will not need professional assistance, and will not need to argue with his local authority over what the bylaw actually means. Keeping the by-law simple has its price too. The home-owner in Auckland will benefit, but not as much as the homeowner in Invercargill. It will even still be possible to build a “cold” house, especially by putting in excessively large windows facing south on an exposed site; but such cases will be rare, and .of little importance on thfe national scale.