The ongoing cost of living and climate crises have many of us looking for ways to reduce energy bills and carbon emissions. One of the biggest expenditures of any household or business, and a significant contributor to greenhouse gas emissions, is heating. Ineffectively insulated properties can increase the environmental and economic impact of heating. It takes more energy to heat a leaky house, leading to greater fuel consumption and, therefore, higher carbon emissions and energy charges Nevertheless, finding insulation issues can be tricky as they are often invisible and soundless. Thermal imaging offers a quick, simple, and cost-effective solution. Below we detail how thermal cameras can be and have been used to find sources of heat loss in houses.
Quick Links
- Why is Energy Efficiency Important?
- How does Thermal Imaging Work?
- What is a Thermal Camera Energy Audit?
- Further Information
Why is Energy Efficiency Important?
Across Europe, the heating of buildings accounts for approximately 40% of energy consumption and 35% of carbon emissions.[1] In the UK, up to 18% of greenhouse gas emissions can be attributed to heating homes.[2] Furthermore, the Office for National Statistics estimated that between April 2022 and January 2023, when the energy price cap was lifted, the average annual energy bill per household increased from £1277 to £4279 (although the Energy Price Guarantee capped consumer payments at £2500).[3] Despite energy prices returning to (roughly) April 2022 rates, the price cap was raised in January 2025 and, according to Cornwall Insight, further increases are expected in April 2025. In fact, analysts at the energy market forecaster advise that “high domestic energy prices are likely to be “the new normal”.[4]
An increasingly volatile energy market, combined with a pressing need to reduce carbon emissions, makes identifying sources of heat loss and improving insulation critical. Correctly insulated buildings will retain heat. As such, they will require less energy to warm; consequently lowering fuel consumption, payments, and emissions.
Previously, inspecting properties for sources of heat loss was laborious, time-consuming work, reliant on seeing gaps, feeling drafts, and noticing condensation. Now, thermal cameras make surveying houses for insulation issues efficient, easy, and precise.
How Does Thermal Imaging Work?
Thermal cameras capture infrared radiation invisible to the human eye and convert it into a visual image, allowing you to see the heat distribution across a scene. Thermal colour palettes indicate the thermal contrast across an area. For instance, white or bright yellow may indicate the hottest point in the picture, whereas dark blue indicates the coldest point. This allows you to see hot and cold spots immediately and ascertain where heat is being lost.
What is a Thermal Camera Energy Audit?
A thermal camera energy audit involves using a thermal imaging camera to survey the inside and outside of a property for heat loss or retention. These audits help to identify energy inefficiencies caused by poorly insulated walls, drafty windows, and poor weather sealing.
Thermal Image UK, Energy Auditors
Generally, energy audits are carried out by a certified technician. Tom Barbour is the director of an energy-auditing business, Thermal Image UK, in Strathaven, Lanarkshire. His company uses thermal imaging to assess where heat is escaping and cold air is entering buildings. He reveals that:
“The technology has been around for years, but it’s only with rising energy costs and the climate crisis that this testing is becoming more commonplace.”[5]
- Tom Barbour, Thermal Image UK
Using thermal cameras, smoke testers, and pressure-testing fans, Tom Barbour and his team gather data and thermal images with accurate temperature readings to determine sources of heat loss and/or cold air. Customers may use this information to address energy inefficiency issues themselves or with the help of a trusted tradesperson or architect, depending on the severity of the problem.
Thermal Imaging UK tends to perform energy audits on older buildings. However, they are occasionally asked to inspect new builds. Tom Barbour explains:
“Most new houses are built to a high standard, but not all get adequate quality checks, and this can result in cold spots that plague homeowners for years.
It’s relatively easy to find with this technology [thermal imaging cameras], and recently we’ve seen an increased level of enquiries from homeowners across Scotland.”[6]
- Tom Barbour, Thermal Image UK
The Price of Thermal Camera Energy Audits
Still, thermal camera energy audits do come with a price attached. However, once energy inefficiency issues have been addressed, the costs recouped through reduced heating bills will cover this expenditure, usually, within a couple of years.
The benefits of energy audits for businesses are doubly apparent. Not only could they reduce overheads, thereby increasing profits, but tenders often require that businesses provide evidence of effective environmental policies. As such, conducting and acting on thermal imaging energy audits may prove critical to securing lucrative contracts.
Using Thermal Imaging for House Heat Loss
Thermal Imaging UK is not alone in offering thermal camera energy audits. In the USA, Glen Valentine, a home inspector located in West Michigan, offers a similar service. In January 2025, Glen Valentine was the subject of a local news report in which he demonstrated how and why thermal cameras are used to uncover sources of heat loss and cold air infiltration.
UK Councils & Companies Provide Thermal Cameras for Energy Audits
Additionally, pressure to meet Net Zero targets combined with increased energy prices has led some companies, charities, and councils to invest in and loan thermal cameras to their patrons. Notably, Wiltshire Council made eleven thermal cameras available to residents. So successful was this initiative, that the council is now operating a waiting list. Similarly, North Somerset Council implemented a thermal camera loan scheme and, like Wiltshire, is also working off a waiting list.
News Roundup: Thermal Cameras Used to Reduce Energy Bills & Carbon Footprints
Moreover, since 2019, Octopus Energy has been encouraging its customers to conduct thermal home inspections. To this end, the company has been lending thermal cameras to customers. The energy supplier has a fleet of approximately 500 cameras (many supplied by PASS Ltd), and, in 2024, distributed these cameras approximately 3800 times.
PASS Proudly Provides FLIR Thermal Cameras for Octopus Energy Home Efficiency Surveys
Decarbonisation Experts Back Thermal Imaging but Advise Caution
However, experts advise against relying solely on thermal imaging gathered through self-performed energy audits. As, without proper training, results may be misinterpreted. Jo Atkinson, senior consultant in buildings decarbonisation at Energy Systems Catapult, a research organisation, explains that:
“If a wall has been warmed by the sun, an image of that wall taken outside could make it look as though heat is escaping, when it is not. Reflective surfaces can also appear, misleadingly, to be leaking heat.”[7]
- Jo Atkinson, Energy Systems Catapult
Dr Ronita Bardhan at the University of Cambridge echoes Jo Atkinson’s concerns pointing out that the thermal camera’s calibration, thermal palette, and position can all make it seem as though areas are leaking heat when, in fact, they are not. She warns against “triggering retrofit anxiety”, as incorrectly altering insulation can lead to other problems such as damp and mould. [8]
Nevertheless, Dr Bardhan does agree that thermal cameras offer a great starting point for understanding your home. However, she cautions that independent expert advice should be sought when planning renovation works.
Wiltshire’s Councillor, Ian Blair-Pilling, reiterates this, saying:
“Expert advice, combined with a measured approach to findings from thermal imaging, will give residents the best chance of making informed decisions about energy-saving home improvements”[9]
- Councillor Ian Blair-Pilling, Wiltshire Council
Experts Encourage Seeking Free Online Training Before Conducting a Thermal Home Inspection
This isn’t to discourage individuals from using thermal cameras as an initial inspection tool. There are plenty of free online resources that can help beginners conduct a basic home inspection. For instance, North Somerset Council offers introductory online advice, as well as a video overview of how to use FLIR’s C3-X and One Edge thermal cameras.
Teledyne FLIR’s Darrell Taylor also advises that FLIR provide some free training materials on their website and that they have designed their cameras to:
"[..] make thermal images as clear and easy to interpret as possible – including by merging optical imagery with thermal imagery, to add more detail to the final picture.”[10]
- Darrell Taylor, Teledyne FLIR
Consulting free online training materials meant Louise Green, a designer from London, could effectively locate sources of heat loss in her home. Renting a thermal camera from the Library of Things, an organisation that makes tools available for people to borrow, she conducted a thermal inspection of her house. Miss Green compared the thermal images of her home to those of her neighbour’s better-insulated house. As a result, she could see that heat was escaping around her windows and doors. She attests:
“It just confirmed what we knew already, but it was still interesting to see.”[11]
- Louise Green
Further Information
For more advice regarding thermal cameras or thermography training, please contact our Sales team on 01642 931 329 or via our online form.
Alternatively, please browse our extensive range of thermal cameras and thermography training courses below.
Please see our following blogs for some initial pointers on using thermal cameras to locate heat loss, infiltrating cold air, and/or insulation issues.
FLIR’s Top Tips for Ensuring Energy Efficiency
Winter Is Coming: Prepare Your Home for the Long Night(s) Using Teledyne FLIR Thermal Cameras
[1] Joe Brawn, Cutting Carbon, ECN, 44.1 (Jan 2024), 60-61.
[2] National Audit Office, Decarbonising home heating, last accessed 17 February 2025.
[3] Office for National Statistics, Census 2021: how homes are heated in your area, last accessed 17 February 2025.
[4] BBC News, What is the energy price cap and how are gas and electricity bills changing?, last accessed 17 February 2025.
[5] Glasgow World, How to prevent draughts and cold: Scottish firm can help identify heat loss in homes, last accessed 17 February 2025.
[6] Glasgow World, How to prevent draughts and cold: Scottish firm can help identify heat loss in homes.
[7] Chris Baraniuk, ‘Could thermal cameras reveal your home’s hidden heat loss?’, BBC News, last accessed 17 February 2025.
[8] Chris Baraniuk, ‘Could thermal cameras reveal your home’s hidden heat loss?’
[9] Chris Baraniuk, ‘Could thermal cameras reveal your home’s hidden heat loss?’
[10] Chris Baraniuk, ‘Could thermal cameras reveal your home’s hidden heat loss?’
[11] Chris Baraniuk, ‘Could thermal cameras reveal your home’s hidden heat loss?’
