Heat Loss from Houses Captured Using Thermal Imaging Camera

Pub in Berkshire, thermal image shows heat escaping through deteriorated roof insulation – where the snow has melted.

WINTER is well and truly upon us and Britons across the country are cranking up their central heating. But just how much of this heat is actually keeping us warm, and how much is escaping from our poorly insulated homes?

Images (captured by the Cat S61 rugged smartphone) show heat escaping from homes of every shape and size across the UK during the cold snap that’s enveloped us this week. The pictures show how poorly insulated many homes are, with heat leaking through gaps in windows, doors, roofs and walls.

Generally, newer houses hold their heat more efficiently –due to modern insulation and double-glazing – however, one image taken in Shoreditch, east London, shows how much heat is lost through the large feature windows of a modern flat (see below).

Another image, taken in the north of the capital shows the stark contrast between a Georgian block of flats and a recently completed modern block built right next to it. The thermal image shows heat being lost through the windows and walls on the old building, whilst the external walls of the modern block are cold showing the heat being kept inside. (see below).


Paul Holmes, Technical Product Manager at Bullitt Group, makers of the Cat S61, said: “When looking at a building using thermal imaging, it’s the contrasting colours that are important to focus on. Yellow and white/yellow spots show heat, and dark plum colours show cold spots. Both of these can be a bad sign because it usually means that either heat is escaping or cold is coming in.

“The lighter or brighter a patch is, the hotter it is, and the bigger the colour difference the bigger the difference in temperature.

“Equally, from the outside of the house it’s important to take note of particularly warm spots as this could be a sign of heat escaping. In general, the goal is for the exterior of your house to be cold – including windows, external walls and the roof – as this means that the heat is staying inside rather than leaking out.”

In a typical British home, around one-third of the heat produced by its heating system is lost through the roof, ceiling and walls, according to the National Energy Foundation.

Anthony Crossman from A-J-C Plumbing said: “It’s worth checking doors, window frames, ceilings and walls inside and outside your property to see if you are losing heat. Loft insulation can also be an issue so it’s worth seeing what heat you’re losing through the roof if you have easy access.”

“The most important tip I have is to have your boiler serviced every year. If you want your heating to work efficiently throughout the winter, you must look after the boiler. A lot of winter break downs can be avoided by correctly servicing the boiler.

Ways to improve energy efficiency

  • Increasing insulation (loft insulation, cavity wall insulation and solid wall insulation)
  • Internal and external draught-proofing (fitting door seals, letterbox brushes and filling gaps in wooden flooring)
  • Servicing or upgrading radiators (thermal imaging technology can help you compare thermal performance before and after)
  • Treating windows and window frames to stop heat escaping (or fitting double/triple glazing for the best results)
  • Insulating pipework and fitting radiator reflectors
  • Filling cracks and gaps in flooring and around fittings/fixtures

The cost of poor insulation
On average, a poorly insulated UK house will cost the homeowner between £168-£250 a year due to heat loss through lofts, roofs, and walls.

According to Which?, without loft insulation of 0-270mm the average sized detached, semi-detached, mid-terrace, and bungalow homes are losing between £120 and £225 a year and adding to unnecessary CO2 wastage:

Type of property Money lost per year CO2 waste (kg)
Detached house (four bed) £225 990
Semi-detached house (three bed) £135 590
Mid-terrace house (three bed) £120 530
Detached bungalow (two bed) £195 850




Please enter your comment!
Please enter your name here