INSULATION
A warm, dry house is essential and spending more on insulation will help to save on heating and maintenance costs. At The Block
NZ, builders have installed high-performing Knauf Earthwool Glasswool throughout the buildings at a higher spec than required, says Peter, reducing noise pollution as well as heat loss.
“In many areas we’ve used 140mm x 45mm framing which allows us to put more insulation into the exterior walls,” he says. “All the internal frames in all levels of the building are insulated well above the code, so instead of using R2.6 we’re using R2.9 and instead of R3.8 we’re using R4.1. Right throughout the building we’re doing more insulation than is required by the Building Code.
“Most New Zealand houses don’t have insulation in their internal walls or mid-floors, because you technically only have to insulate the exterior of the building. We’ve insulated everything. It makes individual rooms warmer and easier to heat. The other benefit is that it makes houses quieter, and I think we underestimate the impact of noise pollution inside houses. If you can hear somebody taking a shower or you can hear the kids’ music, those sorts of things make for a less enjoyable living experience.
“Being able to use 13mm plasterboard gives us one-third more thickness on both sides of each wall. We’ve used Ecoply Barrier (a rigid air-barrier system behind the cladding) on the exterior of the house, which helps to seal the building more effectively. The air barrier gives us weathertightness really early on in the process so the building starts to dry out a lot earlier. I think it’s more robust than a traditional building wrap and it gives us extra thickness on the outside of the building. And while it’s not part of the insulation calculations, I actually believe that it does help.”