Home and dry
Insulation and glazing go a long way to making your home more comfortable and, more importantly, healthier for your family.
WWe all know the resale-based mantra in the housing market which is location, location, location. When looking at homes it is now time to add to this the living comfort-based mantra of insulation, insulation, insulation. This is because well-insulated homes offer a wide range of benefits which easily outweigh the cost involved. • In summer the insulation increases comfort by keeping the house
cooler. • In winter, heating will be retained for much longer in well-insulated homes leading to less heating energy required and to considerable ongoing savings. • Warmer and drier houses will have less condensation, they are less prone to mould and mildew growth. • They will be healthier and more comfortable to live in, reducing the unusually high rate of asthma and respiratory problems in NZ. • Homes with a consistently higher median temperature will be cheaper to maintain because there is less damage caused by dampness and condensation. A large part of our old housing stock is uninsulated, cold and damp – those built before 1979, when insulating new homes became compulsory. In order to help home owners with retrofitting insulation the government through EECA ( www.energywise.govt.nz) and local councils like Auckland City (ph 301 0101 or email: email@example.com) are providing financial assistance.
Some of the approved retrofit items include ceiling and underfloor insulation, ground polythene vapour barrier, and hot water cylinder and pipe wraps.
While installing these will improve the performance of the home there is more we can do in order to complete the job. Ceiling and underfloor insulation are being focused on so far because these areas are easily accessible. But it is of course the whole building envelope that determines heat loss and discomfort in the home, and that includes exterior walls and windows. They have a significant influence on the thermal performance of the home.
Retrofitting insulation into existing walls can be easy when done in the course of renovations where the wall linings are being removed. The other, more delicate, option is to drill holes through the exterior cladding and to blow insulating material into the wall cavities. The choices for these materials should be considered carefully as their performance varies due to a certain amount of shrinkage that can be expected. It has to be said that until technical solutions for this and some other problems have been developed, retrofitting wall insulation has to be treated with caution and requires building consent. The options are • Cellulose insulation, which consists of old newspapers treated with borate salt to allow resistance against rodents, bacteria, fungi and fire. It begins to settle the moment it is installed by 10% or more and will depend on the density it is installed at. • Loose-fill rockwool (mineral fibre) insulation generally settles less than cellulose but again the amount will depend on the installed density.
While new houses will all be insulated as a consequence of today’s Building Code requirement, their thermal performance can be greatly improved by increasing the prevailing choice of 90 mm wall studs to 140 mm ones. This allows for an extra layer of insulation.
Generally it is important to remember that for insulation to work effectively it must be installed correctly. There should be no slumping and no gaps as this can lead to considerable heat loss. For more information on these topics Auckland Council provides free and independent eco design advice. Phone 0508 326-337. To assess the performance and health of your home check out homestar.org.nz
Retrofitting insulation into existing walls can be easy when done in the course of renovations where the wall linings are being removed.