How Conveyancing Addresses Radon Risk
During a standard UK conveyancing transaction, your solicitor commissions an Environmental Search (e.g., Groundsure Homescreen or Landmark Envirosearch).
This report interrogates BGS/UKHSA datasets. If the property sits in an area where more than 1% of homes exceed the Action Level, the report issues a formal advisory note.
Because a valid radon test requires 3 months of passive detector placement under normal living conditions, buyers rarely have time to complete a physical test before exchanging contracts. The conveyancing profession developed two standard solutions:
1. Ask the Seller for Previous Tests: The seller may have already commissioned a UKHSA test. If valid and under 100 Bq/m³, the buyer can proceed with confidence.
2. Establish a Radon Bond (Retention): The buyer and seller sign a special contract clause where the buyer's solicitor holds back an agreed sum (usually £1,000 to £2,500) from the sale purchase price upon completion.
| Step | Timeline | Action Taken | Financial Responsibility |
|---|---|---|---|
| 1. Contract Agreement | Before Exchange | Solicitors draft retention clause in contract | Both parties agree retention amount (£1,500) |
| 2. Completion | Day 1 | Buyer moves in; £1,500 held in seller solicitor escrow | Seller receives sale price minus £1,500 |
| 3. 90-Day Testing | Months 1–3 | Buyer places 2 detectors in living room and bedroom | Buyer pays £50 detector lab kit fee |
| 4. Lab Analysis | Month 4 | UKHSA lab issues official Bq/m³ certificate | Official report sent to solicitors |
| 5A. Result Below 200 Bq/m³ | Month 4 | Radon is safe; retention released to seller in full | Seller gets full £1,500; transaction closed |
| 5B. Result Above 200 Bq/m³ | Months 4–5 | Retention funds professional sump/PIV installation | Installer paid directly from the £1,500 escrow |
Remediation Systems: Simple & Inexpensive
Prospective buyers often confuse radon with asbestos or structural subsidence, fearing crippling remediation bills. In reality, radon mitigation is simple building physics:
• Positive Input Ventilation (PIV): A quiet loft-mounted fan introduces filtered, positive air pressure into the house, gently pushing radon gas out through external vents and door perimeters. Cost: £700 – £1,200.
• Active Sub-Floor Radon Sump: A small pit excavated beneath a solid floor connected to an external 100mm pipe and low-wattage fan extracts gas before it enters living spaces. Cost: £1,200 – £2,200.