Buying a House With Radon

Buying a house is a significant milestone, but when the property is located in a radon-affected area, additional considerations come into play.

Radon, a naturally occurring radioactive gas, is prevalent in certain regions due to geological factors.

Partner Mike Bracegirdle demystifies radon and tells you what you need to know to make an informed decision on whether to continue with your purchase.

What is radon?

Radon is a naturally occurring radioactive gas which is both colourless and odourless. It is formed through the decay of uranium in rocks and soil. Radon poses a significant health risk when it accumulates indoors, especially in poorly ventilated spaces, as it can damage lung tissue.

Why do homes have radon?

Radon has the propensity to collect in enclosed spaces such as houses. The level of radon in homes is influenced by the underlying geology, the building’s construction and the activities of the people living in the property. However, there are steps you can take to reduce radon in your home.

What is a safe level of radon?

According to government guidelines, the risk from radon is considered low if levels stay below 100 Bq/m3 (the UK average is 20 Bq/m3). If the radon level is above this threshold, it’s important to take action to lower it.

What are the effects of radon in your house?

Exposure to elevated levels of radon poses health risks, particularly to lung health. Prolonged exposure increases the risk of lung cancer, making it a serious concern for homeowners. While the risk is relatively low at lower concentrations, it’s essential to mitigate exposure, especially in radon-prone areas.

Which buildings are affected?

Typically, those in a high radon affected area especially those with a basement or cellar or which have been built into a hillside.

On any property purchase, we recommend conducting a full suite of searches. The local search will advise if the property is in a radon-affected area, and the environmental search will provide further details.

However, being in a radon-affected area does not mean that you should automatically withdraw from property purchase as there are radon protection measures you can take.

How can you mitigate the risk from radon?

Fortunately, there are effective mitigation strategies to reduce the dangers of radon gas in the home.

Radon mitigation system

A radon mitigation system can be purchased and installed, costing between £1000 and £4000 depending upon the property.

This cost should be considered when negotiating the purchase price of the property. If the property is relatively modern, the builders may have taken into account the radon risk and factored this into the construction.

Your surveyor should make further enquiries or carry out tests to determine what steps were taken when the property was constructed.

As part of the conveyancing process, we will enquire about any documentary evidence of such works being carried out.

If it is not possible to ascertain if any preventative work was carried out during the property construction or if the seller is not prepared to stand the cost of the installation of a radon mitigation system, we can discuss alternative options with you.

Radon Bond

A radon bond is a contractual agreement between the buyer and seller of a property in a radon-affected area. It outlines the terms and responsibilities related to radon mitigation measures. Essentially, it serves as a financial arrangement to address radon issues discovered after the property purchase.

In a radon bond agreement, both parties agree on how the costs of radon mitigation will be covered if elevated radon levels are detected after the sale.

This may include the installation of radon mitigation systems or other remedial measures to reduce radon levels in the property.

The terms of a radon bond should be fair and equitable to both the buyer and seller. It typically includes provisions for assessing radon levels, determining appropriate mitigation measures, and allocating the financial responsibility for mitigation costs.

Radon bonds provide buyers with assurance that any radon-related issues discovered after the purchase will be addressed in a timely and cost-effective manner.

They also give sellers the opportunity to disclose any known radon risks upfront and negotiate the terms of mitigation as part of the sale agreement.


More commonly buyers seek a bespoke insurance policy from the seller, which covers the costs associated with mitigating radon issues in a property.

The insurance policy would cover expenses related to addressing radon-related problems, such as installing radon mitigation systems or conducting remedial actions to reduce radon levels.

Most policies provide that the owners will need to maintain regular testing and ensure that the property is kept well-ventilated. Most standard house insurance policies do not cover radon.

Passive Pump

A more long-term solution is a passive pump. The fan blows fresh air (often from the roof space) into the property or via the floor space if the floor is a suspended construction.

Radon should not be ignored when purchasing a property but should be investigated and a view taken with the help of your surveyor and tests to establish the levels.  In most cases, there will be a cost-effective solution.

Is radon testing required to sell a home?

Radon testing is not a legal requirement for selling a home. However, it is highly recommended by the UK Radon Association, especially in areas known for high radon levels.

While it’s not mandatory, many homebuyers may request radon testing as part of their due diligence process.

In some cases, mortgage lenders may also require radon testing before approving a loan, particularly for properties located in radon-prone areas.

Therefore, while not compulsory, radon testing is likely to be an asset in the buying or selling process.

Should I buy a house with a radon mitigation system?

Buying a house with a radon mitigation system can offer several advantages. Radon is a naturally occurring radioactive gas that can seep into buildings, potentially posing health risks.

A property with an already installed mitigation system indicates that radon levels have been addressed and reduced to safer levels, providing peace of mind for the buyer.

Installing a radon mitigation system can also be costly and disruptive, so purchasing a house with one already in place can save both time and money.

Before making a decision, it’s advisable to have the property inspected and obtain radon level measurements to confirm that the mitigation system is adequately reducing radon levels to acceptable standards.

How can Butcher & Barlow assist?

Navigating the complexities of buying property in a radon-affected area requires expert guidance.

Partnering with experienced professionals, including solicitors, surveyors, and radon specialists, can provide invaluable support throughout the process.

They can help assess radon risk, negotiate mitigation costs, and ensure compliance with legal requirements.

If you’re considering purchasing a property in a radon-affected area, do not hesitate to reach out to Butcher & Barlow for expert advice and assistance in navigating this important aspect of property buying. Your peace of mind is our priority.

Please get in touch with our Residential Property Solicitors via or directly with your nearest office to arrange an initial meeting.


Mike Bracegirdle

Mike Bracegirdle