Thermal Imaging Project

Last winter, Sustainable Didcot ran a thermal imaging project within the town. We borrowed a thermal imaging camera from SODC to carry out surveys of peoples homes during January and February 2017. We surveyed 33 houses in total as well as the Baptist Church and the offices of Go Green Taxis.

This followed on from the successful project we ran in Didcot from November 2015 until the end of January 2016. We surveyed 35 houses and many other well known buildings around Didcot - see below for the results.

We are planning to have a year off and so will not be running a project 2017/2018.

We have put together an interpretation guide to help understand the thermal images that we took:

If you have any questions, you can contact us by emailing

or through our Facebook page

What is thermal imaging?

Thermal imaging works by detecting the infra-red radiation emitted by a building and using it to determine the temperature of the surface of walls, windows, doors, roof etc. Objects at different temperatures emit varying amounts of infra-red and the infra-red camera translates these differences into an image with different colours representing cool (blue/purple) to hot (white/red) temperatures. This process is called 'thermography' and Wikipedia has a good article explaining it and giving examples of its applications.

The infra-red radiation cannot pass through glass and so the camera cannot see through the windows (or doors, walls etc.). This means that a thermal imaging survey will not invade your privacy, and what we are seeing in the images is the outside surface of the house. Glass actually reflects infra-red radiation, so any shapes you may see in pictures of the windows will be due to reflections from outside.

A thermal image of the outside surface of your house is useful because it can show areas which maybe conducting heat from the inside to the outside of the house. Ideally insulation, either in a cavity inside the walls or in a layer in the loft, should minimise the heat loss through the walls or loft. However, if there are gaps in the insulation, or places where it has been bridged by a conducting structure, then we will see a hotter pattern on the outside surface. Similarly for windows and doors, we can see in the image if there is a poor seal around them that is letting warm air escape, or if they are poorly insulated (e.g. single glazed windows).

What can you learn from a thermal imaging survey?

If your house is relatively new, already has insulated cavity walls and double glazing and feels warm:

    You might not learn much, except to get an even warmer glow after confirming your house is well insulated!

If your house is older and seems difficult to keep warm:

    You might learn exactly where the heat is escaping and get some ideas about where to insulate

A thermal imaging survey might

  • identify places which might have draughts
  • detect whether cavity wall insulation is patchy or missing
  • detect areas with less loft insulation (although roofs are tricky to image with the camera)

Why did we run the project?

South Oxfordshire District Council have a thermal imaging camera that they loan out to community groups to carry out surveys in their areas, and this meant that we had the means to run surveys for free. Our aim in running the project is to raise awareness about insulation, and if possible help people to improve the energy efficiency of their houses. This will mean both a reduction in fuel bills, and also reducing the total amount of carbon dioxide that we emit into the atmosphere which is important for stopping climate change.

Several other communities in the district have run similar projects in the past - you can read more about some of their results here:

What were the results?

We made three posters to summarise the results from winter 2015/2016 - click on the images below to enlarge and read!


We also had an exhibition in the Cornerstone Window Wall during October 2016 showing some of the images - here is a picture in case you missed it:

Sustainable Didcot,
Aug 2, 2017, 3:07 AM