Beacon

Cold, damp homes can affect your family’s health: New Zealand has the second highest rate of asthma in the world, and an excess winter mortality rate of 1,600. In other words, the death rate is 18% higher in winter than during the rest of the year, a figure which is high by world standards.

Insulation creates a barrier that slows the transfer of heat from the inside of your house to the outside. It’s the most effective way to keep your house warm; a well-insulated house requires less heating (or cooling) to maintain a given temperature.

As insulated surfaces are warmer, condensation is less likely to form on them. As a result, an insulated house will have less mould and mildew, and be a less appealing environment for allergy-aggravating dust mites.

About 900,000 homes across New Zealand were built before 1978, when insulation became mandatory. Even if your house has been insulated, it may be worth checking to ensure it is still performing well: older insulation may have settled or may not be as thick as required by today’s standards, reducing its effectiveness.

For maximum effectiveness, coverage around the building should be unbroken. However, insulating one part at a time will provide some benefits. Most heat (about 42% in an uninsulated home) is lost through the ceiling, the ceiling is also relatively easy to retrofit.

Walls are typically responsible for 24% of heat loss; as it is necessary to remove the internal lining to retrofit insulation, this is a more difficult exercise. However, if you are renovating, it is well worth insulating the walls at the same time.

While only about 10% of heat is lost through the floor, this area is relatively cheap and easy to insulate. Underfloor insulation also reduces dampness: most moisture enters the house from underneath, otherwise known as rising damp.

Resistance values (R-values) measure the effectiveness of different insulation types. The higher the R-value, the better the barrier and the more effective the insulation.

As well as insulating the building, insulating your hot water system is a quick and cost-effective way to improve your home’s energy efficiency: heating hot water makes up about a third of the average power bill, so if your hot water cylinder is not A-rated, get it wrapped.