Recently I had the once-in-a-lifetime opportunity to borrow a Thermal Imager/ Camera. A serious bit of kit. Cheers Paul.

This camera measures light at the infra-red (heat) part of the spectrum rather than visible light. It allows you to take photos which show the temperature of surfaces rather than their color/ brightness. Really handy for checking for cold spots in a house interior.

For example below, the surface temperatures vary from -2C (purple) to 0-ish (orange):

I waited for a really cold morning (+2° outside) before using:

Executive summary: there were no unexpected places of heat loss inside the house which is good news, and a testament to the conscientiousness of the builders in placing the bulk insulation, and tape sealing the inner semi-permeable membrane.

Typically the tile floor temperature was around 13° (represented as white/ yellow below) & the bottom of window & door frames around 10.0 to 10.5°, so 3° or less difference (represented as purple/ black below) . The PVC frames perform worse than the glass as expected:

The cross section of the triple glazed PVC window frame sill shows why the heat conduction is so low:

The door locking mechanism with the solid steel through‑bolt being the worst thermal bridge, also as expected, although still only 3° difference:

The unsealed section of the laundry ceiling around the Heat Recovery & Ventilation (HRV) ducting, and specifically against the laundry/ carport wall was a large cold‑spot, ceiling ~11° – wall ~8° = 3° difference:

still probably worth trying to seal the ceiling better in future

The extra insulation around the big 190 dia. ducts is clearly working well, with little temperature difference compared to other laundry surfaces:

Even with lots of lagging (lots more than the plumber originally installed), there is still room for improvement in reducing the hot water cylinder pipework heat loss; maybe an insulated box sometime in the future: