What it is
Airtightness is the difference between a home that holds its warmth and one that leaks it through a thousand small gaps. A continuous airtight layer wraps the frame, every joint and penetration is taped, and the result is measured with a blower-door test rather than guessed at.
How we build it
We build the airtight layer in from the start: Pro Clima membranes across the structure, joints and junctions taped as the frame closes up, and services planned so they pierce the layer as few times as possible. Pro Clima runs across our whole range of homes; the one exception is The Black House, whose Formance SIPs envelope is sealed with silicone. On homes built to the Passive House standard, like The Green House at Upper Moutere, we run a blower-door test and seal every leakage point it finds.
Good questions
Airtightness, answered.
What does airtightness mean in a new build?
It means the building envelope is sealed as one continuous layer, with every joint, junction and penetration taped, so warm air stays inside instead of leaking out through gaps you cannot see. It works hand in hand with insulation and ventilation.
What is a blower-door test and do you do one?
A blower-door test pressurises the home with a calibrated fan and measures exactly how much air is leaking, and where. We run one on every home built to the Passive House standard, like The Green House at Upper Moutere, and seal every leakage point it finds.
Do you use Pro Clima on every home?
Yes, on almost all of our builds. Pro Clima INTELLO membranes and tape systems run across our whole range; the one exception is The Black House, whose Formance SIPs envelope is sealed with silicone instead.
How airtight does a home need to be for Passive House?
The Passive House standard sets a strict air-changes-per-hour (ACH) target, verified by a blower-door test rather than estimated. It is far tighter than the New Zealand Building Code minimum, which is why we test and seal, rather than guess.
Does an airtight home still need ventilation?
Yes, and this matters. An airtight home cannot rely on gaps to breathe, so we always pair airtightness with heat-recovery ventilation, bringing in fresh, filtered air without losing the warmth you have just sealed in.
Talk to the builder who does this every day.
Book a free one-hour consultation with founder Daryl Combes. No obligation, just an honest conversation about your site, your brief and your budget.
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