PowerSwitch

For some reason, I bought a handheld 'pistol' type remote thermometer some time ago.

Just-for-fun I wandered around with it in the current cold weather. -4C outside, about 17C inside.

I was surprised to find that:

1. The triple glazed units work well BUT the narrow wood frame the windows sit in is not as well insulated as the glazing.
13C along the border strip, 17C - 18C a few inches further along the wall.

2. The lower two or so feet of the triple glazing panels are colder at 13C - 14C or so.

I have now inserted hand cut polystyrene strips around the windows.

I have also taped up a 2 ft high run of bubble wrap along the triple glazed doors and adjacent panels.
This may help as an insulator and also as a draft excluder, just in case the seals aren't perfect.

Hopefully this will make help our valiant heat pump keep the place warm.

(ideally I should check the place with an IR imaging camera - but they are expensive to buy or rent)

You should definitely go for the IR camera. I got a FLIR for USD500 when the Aussie dollar was at an all time high and even told the taxman, via my accountant it is for work and get a $45 tax credit every year for it.

You can see areas of poor insulation glowing like a pool of lava during hot days and during cold days see the effect of cracks between the wall and the floor and even eerie blue tracks where cold draughts are cooling solid surfaces. You can see as clear as day the limits of the foam I got sprayed into my 'cavity' wall looking like a bathtub ring on the inside walls close to the ceiling.