Radon Specialists in the UK
Browse 4 verified radon specialists across the UK. Get quotes for Radon Risk Assessment, Radon Mitigation Design and more.
4 verified radon specialists across the UK on The Planning Review.
What does a radon specialist do?
A radon specialist assesses the risk of radon gas at a development site and designs protective measures to prevent it entering new buildings. Radon is a naturally occurring radioactive gas produced by the decay of uranium in rocks and soils. It is colourless and odourless, and prolonged exposure to elevated indoor concentrations is the second largest cause of lung cancer in the UK after smoking. Certain geological areas (notably Devon, Cornwall, Somerset, Northamptonshire, Derbyshire, and parts of Wales and Scotland) have significantly elevated levels, and new buildings in these areas must incorporate radon protection under Building Regulations.
The specialist's work starts with a radon risk assessment using UK Health Security Agency (UKHSA) radon maps and site-specific data to determine the site's radon potential. This establishes whether protective measures are required under Building Regulations Part C and what level of protection is needed. Lower-risk sites may require only a basic radon barrier (a sealed membrane across the ground floor). Higher-risk sites require full radon protection: a radon barrier plus a radon sump system (a void beneath the floor slab connected to extraction pipework that can be activated if post-construction testing shows elevated levels).
Although radon protection is primarily a Building Regulations matter, some LPAs in high-radon areas condition radon assessments and protection details on planning permissions, particularly for larger residential schemes. The specialist's role extends to post-construction testing, where radon levels are measured over at least three months using passive detectors to confirm the protection is working. If levels exceed the action level of 200 Bq/m3, the specialist designs and installs active mitigation (typically a fan connected to the pre-installed radon sump).
When do you need a radon specialist?
- The development site is in a radon Affected Area as defined by the UKHSA radon maps (1% or more of homes estimated above the action level)
- Building Control requires radon protective measures under Approved Document Part C and you need specialist design for the barrier and sump system
- The LPA has conditioned a radon risk assessment or radon protection details on the planning permission
- You are building in a high-radon area (Devon, Cornwall, Somerset, Northamptonshire, Derbyshire, or other identified areas) and need to determine the appropriate level of protection
- Post-construction radon testing has revealed indoor levels above the action level of 200 Bq/m3 and remediation is needed
- You are converting or extending an existing building in a radon Affected Area and need to assess whether radon protection should be installed or upgraded
- The development involves a basement or below-ground habitable space in a radon Affected Area, requiring enhanced protection design
- You are purchasing a property in a high-radon area and want a radon test to establish current indoor levels
Services you can get local quotes for
- Radon Risk Assessment & Protection
Frequently asked questions
How much does a radon risk assessment cost?
A radon risk assessment is relatively inexpensive. The UKHSA radon report for a single site address costs approximately £50 to £100. A specialist's interpretive report, including Building Regulations compliance recommendations and radon protection specification, typically costs between £300 and £800 depending on the complexity of the development. The design of radon protective measures (membrane specification, sump layout, pipework routing) for a standard dwelling typically costs £500 to £1,500. Post-construction radon testing using passive detectors costs approximately £40 to £60 per detector (two are usually placed per dwelling), plus the specialist's reporting fee.
How long does the process take?
A radon risk assessment can be completed within 1 to 2 weeks. Radon protection design is typically prepared alongside the detailed building design and takes 1 to 2 weeks. Post-construction radon testing requires a minimum exposure period of three months (the UKHSA recommends detectors are left in place for the full three months for reliable results), with laboratory analysis and reporting typically completed within 2 to 3 weeks of detector return. If remediation is required, a radon sump fan can usually be installed within 1 to 2 days, with follow-up testing over a further three months to confirm effectiveness.
What is the radon action level?
The UK radon action level is 200 becquerels per cubic metre (Bq/m3), measured as an annual average indoor radon concentration. If the average radon level in a home exceeds this threshold, remedial action is recommended. There is also a target level of 100 Bq/m3, which is the level that remediation measures should aim to achieve. For new buildings, the objective is to design radon protection that prevents indoor levels from exceeding the target level. The action level and target level are set by the UKHSA based on the health risk evidence for radon exposure and lung cancer.
Is radon testing mandatory for new builds?
Post-construction radon testing is not a statutory requirement under Building Regulations, but it is strongly recommended by BRE guidance (BR 211) for all new buildings in radon Affected Areas. Some Building Control bodies and NHBC require evidence of radon testing before issuing completion certificates for new dwellings in high-risk areas. Additionally, some LPAs condition radon testing and the submission of results on planning permissions for residential developments. Even where not formally required, testing is the only way to confirm that the installed radon protection is working effectively, and it is good practice for all new buildings in Affected Areas.
Do I need radon protection for an extension?
If you are extending an existing building in a radon Affected Area, Building Regulations Part C applies to the new ground floor area of the extension. The extension should incorporate radon protection to the same standard as a new building on the same site. For a basic extension on a low-risk site, this means a sealed radon barrier membrane across the new floor slab. For higher-risk sites, a radon sump may also be required. If the existing house does not have radon protection, it is good practice — though not always a Building Regulations requirement — to take the opportunity to install protection retrospectively, particularly if the extension work provides access beneath the existing floor.
Which areas of the UK are most affected by radon?
The highest radon levels in the UK are found in areas with granite and limestone geology. Devon and Cornwall have the highest proportion of affected homes, followed by Somerset, Northamptonshire, Derbyshire, and parts of the Peak District. Other significant areas include parts of Wales (Powys, Ceredigion), Scotland (Highlands, Aberdeenshire, Caithness), and Northern Ireland. However, radon levels can vary significantly over short distances, and elevated levels are occasionally found in areas generally considered low-risk. A site-specific radon report from the UKHSA is the only reliable way to determine the radon potential for a particular location.
Legal and regulatory framework
- Building Regulations Approved Document Part C (Site Preparation and Resistance to Contaminants and Moisture) — requires that reasonable precautions are taken to prevent the ingress of radon gas into new buildings where the site is in a radon Affected Area. The level of protection depends on the radon potential of the site.
- BR 211 (Radon: Guidance on Protective Measures for New Buildings) — the BRE guidance document setting out the design and installation requirements for radon protection in new buildings, including radon barriers, sumps, and ventilation provisions. This is the primary technical reference for radon protection design.
- BRE Report BR 376 (Radon: Guidance on Protective Measures for New Dwellings) — supplementary guidance providing additional detail on radon protection installation, testing, and remediation in residential buildings.
- Public Health England (now UKHSA) radon maps
- The Ionising Radiations Regulations 2017
- NPPF
Professional accreditations
- British Occupational Hygiene Society
- Institution of Occupational Safety and Health
- UK Health Security Agency
- UK Radon Association