Radon Mitigation

Radon is a naturally occurring radioactive gas that can build up in buildings. It's the second leading cause of lung cancer after smoking. Public Health England estimates radon causes around 1,100 lung cancer deaths per year in the UK.

A radon sump system typically costs £800-£1,500 installed. More complex cases can cost £2,000-£3,000.

Check the UK Radon Map at ukradon.org. Parts of Cornwall, Devon, Somerset, Northamptonshire, and Derbyshire have the highest levels. Your local authority can also advise whether your property is in a radon-affected area.

The recommended method is a 3-month passive test using two detectors placed in different rooms. Testing kits cost £30-£50 from UK Radon (ukradon.org). Short-term digital monitors (£50-£200) give quicker readings but are less accurate for long-term risk assessment.

The UK Action Level is 200 Bq/m³ (becquerels per cubic metre). Above this level, remediation is strongly recommended. The Target Level for new buildings is 100 Bq/m³. There is no truly safe level of radon, but risk increases significantly above 200 Bq/m³.

The most effective method is a radon sump (active or passive), which extracts gas from beneath the floor. Other options include positive pressure ventilation, natural underfloor ventilation, sealing cracks and gaps, and radon barriers for new builds. A specialist will recommend the best approach for your property.

Radon testing is commonly requested during property conveyancing in affected areas. A high radon level does not prevent a sale, but buyers may request mitigation as a condition. Having a radon mitigation system already installed can actually reassure buyers.

Yes. Building Regulations require radon protection in new buildings in affected areas. This typically involves a radon barrier membrane and may include a sump for passive or active ventilation. Your builder must comply with BR 211 (Radon: Guidance on protective measures for new buildings).