Deep Reno in NZ - intello to walls only?
Have a big Reno / energy retrofit on a 1990s house, and will be introducing an internal service cavity. In Manawatu.
Some the ceilings in the house will remain, some will be removed.
I had planned on using intello behind service cavity aka like most high performance houses in NZ, on the exterior walls.
Is it worth it, if doing walls only? Or the airtightness layer is so compromised that it’s not worth it?
Context - brick cladding, two storey in part. Recessed UPVC window replacement, service cavity. Generally heaps of roof space - 40 degree roof pitch, other than two storey bit. MHRV unit going in. Sort of like a FHB “pretty good house” approach.
For those not from New Zealand - Manawatu pretty mild climate - a cold night in winter would be -4c, always rising to at least 5c. Summer is 20-24c . Pretty windy.
Don’t want to model or blower door test, as I’d rather just spend that extra doing things better.
Am licensed carpenter and designer and have designed previous high performance houses - but new only.