I have just borrowed a thermal camera from octopus and found it very useful in finding cold spots around the house where I never expected them
I found some gaps in the cavity wall insulation installed in a Government scheme a few years back, found the relatively recently double glazing frames had cold spots.
My house was built about 1995 so recent. I have come to the conclusion that British building standards are so low and there are very few checks on quality of workmanship being carried out