Radon Remediation in Dundrum, Dublin

An active radon sump system for a standard semi-detached house costs €800 to €1,500 installed. More complex installations (larger homes, multiple sumps, difficult access) can reach €2,000. Radon barrier membranes for suspended timber floors cost €1,500 to €3,000 depending on the floor area. Follow-up testing should be included in the price or costs €50 to €70 separately. Annual running costs for the sump fan are approximately €30 to €50.

You must test. Radon is invisible and odourless, so there is no way to detect it without a measurement device. The EPA sells postal test kits for approximately €50. Place the detector in a frequently used ground-floor room for three months, then return it for analysis. The EPA's radon map at epa.ie gives a general indication of risk by area, but individual homes vary enormously even within the same street. Every home in Ireland should be tested regardless of area risk level.

The Irish reference level is 200 Bq/m³ (becquerels per cubic metre). Homes above this level should take remedial action. However, there is no truly safe level of radon: risk increases proportionally with concentration and duration of exposure. The World Health Organisation recommends a reference level of 100 Bq/m³. If your test result is between 100 and 200, remediation is advisable, especially if you are a long-term resident or if smokers live in the home (radon and smoking together multiply lung cancer risk significantly).

A properly installed active sump system reduces radon levels by 90% or more in the vast majority of cases. A home with a pre-remediation level of 800 Bq/m³ can be brought below 80 Bq/m³. The system works continuously and maintains low levels as long as the fan is running. Post-installation testing confirms the reduction. If the initial system does not achieve sufficient reduction (rare), modifications or a second sump can be added.

High radon is not a legal disclosure requirement when selling property in Ireland. However, informed buyers (especially those with young families) are increasingly testing during the purchase process. Having a remediation system already in place, with documented post-installation test results showing low levels, gives buyers confidence and removes a potential objection. Remediation is inexpensive relative to property values and is a net positive for saleability.

The EPA radon map shows that high-radon areas are concentrated in the west, northwest, and parts of the midlands, with notable hotspots in counties Galway, Mayo, Sligo, Clare, Kerry, Waterford, Kilkenny, and Carlow. However, elevated radon has been found in every county in Ireland, including Dublin. Ground conditions, not geography alone, determine radon levels. The only reliable way to know your home's level is to test it.