Keeping the heat

It was only in the immediate post-war years that insulation began to feature in New Zealand houses. Prior to that, the inhabitants took it for granted that heat would escape through the ceiling or through loose doors and windows, and in the absence of a solution, the ‘harden up’ approach prevailed.

According to BRANZ.nz, early Maori houses were often better insulated than those of European settlers, because of the materials they used. Maori often built with earth, which is a good thermal performer. As part of current moves towards more sustainable homes, it is enjoying renewed popularity.

While the idea of insulating homes in order to reduce mould and mildew and improve the health of those living within did catch on in the 1940s, it was to be many years until it was put widely into practise.

This is partly because the materials that were used at the time had to be imported into the country.

We finally began producing a local type of insulation made from fibreglass here in the early ’ 60s, and, by the ’ 70s local and central government were on board with promoting its use — including television campaigns featuring walking, talking bales of pink batts.

Heat is lost through means of conduction, so the aim is to slow down or eliminate this waste.

Experts use a system called R-values, first introduced in the mid’40s, to rate a particular form of insulation’s effectiveness at achieving this.

The higher the R-value, the better your insulation will work at keeping your home warm and dry.

Since 1977, insulation has been mandatory and the levels to which it is used have ramped up markedly, both in new-builds and in retro-fits. There are many options for builders and homeowners to choose from, depending on their own particular goals and requirements. And, no longer confined to insulating ceilings, new homes should have wall and under-floor insulation too.

“Many studies have identified the benefits of insulation, including improved health, greater comfort and reduced heat loss. Quality, wellinstalled insulation is now recognised as the most critical factor in what we call the thermal envelope of the home,” says Andrew Caseley, the Chief Executive of the Energy Efficiency and Conservation Authority (EECA).

Insulation is a big investment, so it’s important to look at appropriate options in terms of where and how you live.

While there are many choices in the insulation market there are also plenty of experts who can help you evaluate your own property and decide what it needs for the ultimate in warm, dry homes.

There’s also lots of useful information at: energywise.govt.nz