Insulation Estimating Services in New Zealand

Building Code clause H1 (Energy efficiency) sets minimum thermal performance. Changes introduced from 2021 split New Zealand into six climate zones and raised minimum R-values for roofs, walls, floors and windows, with further increases phased in through 2023. We measure the products specified on your consented drawings rather than assume the minimum.

Bulk insulation in residential buildings is commonly installed to NZS 4246, which covers clearances around downlights and flues and installation without gaps. We count downlight clearances where they affect quantities.

We measure and price to the drawings. Design compliance and building consent remain with your designer and building consent authority.

Where insulation estimates go wrong

Insulation estimates often use an old default R-value from a previous job, which may not meet current requirements. We always measure the specified product.

Another common miss is the less obvious elements: garage walls next to living spaces, skillion roofs, slab edges and internal acoustic insulation. Each needs its own product and quantity.

Gaps and compression are the third issue. Insulation only performs if it fills the cavity without gaps or squashing, and that takes care around services, nogs, downlights and junctions. Labour rates that assume an open, simple cavity will be too low on a home with many services runs or complex framing. We note the elements where installation is more involved, such as raked ceilings, skillion roofs and walls with heavy services, so installers can price the extra care those areas need and inspections pass the first time. Where the specification calls for a vapour control layer or air barrier, we measure it too, because taping laps and penetrations adds labour that installers need to see. We also count downlight covers or clearances where the lighting plan shows recessed fittings.