FAQs on Radon

How does radon get into buildings?

Radon comes from the ground and gets into buildings mainly through cracks in floors or gaps around pipes or cables. As the pressure inside a building is slightly lower than the pressure outdoors, radon will be drawn from the ground into the building. This phenomenon is known as pressure-driven flow.

What is a typical radon level in a house in Ireland?

Radon levels vary from house to house depending on where the house is located, its construction type and how it is used. The average indoor radon level in Irish houses is 77 becquerels per cubic metre (Bq/m3), although levels up to 550 times this value have been measured.

Is a neighbour's radon test result a good indication of the radon level in my home?

No. Radon levels vary from house to house. The only way of knowing the level in your house is to have a measurement carried out in your own house.

Could radon account for other illnesses apart from lung cancer?

No. According to current scientific knowledge, there is no other proven health effect associated with radon exposure. The risk of developing lung cancer depends on the level of radon present and the time one has been exposed.

What level of radon in a house should give cause for concern?

The national Reference Level for long-term exposure to radon in a house, above which the need for remedial action should be considered, is 200 Bq/m3. Measurement should be made using two radon detectors each placed in a bedroom and a living room for at least three months. The average of the two rooms is seasonally corrected to take account of the months of the year that the measurement was made, and it is this seasonally corrected average that is compared to the national Reference Level.

How long does a measurement take?

The EPA recommends a minimum measurement duration of three months. This is because there can be significant day to day variations in radon levels. Therefore the only way of confidently assessing your radon risk is by carrying out a three month test.  Only the results of a measurement made over at least three months can be compared to the national Reference Level.

Can unoccupied or holiday homes be tested for radon?

Yes. However it is likely that the result will be higher than when the home is occupied.  This is because once the home becomes occupied there will be greater ventilation from people opening windows and doors which will act to reduce the radon level.  The EPA strongly recommends that a radon test is carried out when a home is occupied.

Can I do a radon measurement over a shorter period?

Yes. A short term test can be useful in giving an indication of the radon levels in a home.  For example if work has been carried out to reduce high radon levels in a home, a short term test may be used to give an early indication as to whether the work has been successful.  However, a three month test will still be needed to determine if the radon levels are below the national Reference Level.  Short term radon measurements of a few days are not recommended as a basis for deciding whether or not you have a radon problem.

How frequently should I test my home for radon?

There is no need to re-measure unless you carry out major refurbishment work to your house. For example fitting new windows or building an extension and other such work that could in theory open up new entry routes for radon or prevent radon escaping from your house.

Is there a radon grant to help me with the cost?

There is no grant available to cover for the cost of radon remediation. Some radon reduction techniques are more expensive than others and each one will need to be assessed on a case by case basis. However the typical price for retrofitting a radon sump into a standard house is approximately €925 (ranging from €400-€1500). Other, less expensive options are available, for example, improving the ventilation in your home by installing extra wall vents. However, the most suitable method will depend on the radon levels and on the type of building.

A Scheme of Housing Aid for Older People is available to assist older people, generally over 65 years, to have repairs or improvements carried out to their homes. Where a suite of works is being grant aided under this scheme, Local Authorities may also, as part of the package of works, assist with the provision of radon remediation works, where applicable. Contact the Housing Section of your Local Authority for further information. Additional information is also available from Citizen Information website.


I am building a new house - what radon prevention measures are required?

Specific guidance on radon prevention measures for new homes is contained in this document which is published by the Department of the Environment, Heritage and Local Government.

This Guidance specifies that all homes built since 1st July 1998 must be fitted with a standby radon sump which can be activated at a later stage, to reduce high radon concentrations subsequently found. For homes built in High Radon Areas, the installation of a radon barrier as well as a standby radon sump is required.

I am building a new house – can I have the site tested for radon?

Although techniques are available for measuring radon levels in soil, it is very difficult to determine what the level in a new house will be from the results of soil measurements. For this reason, the EPA does not consider site radon measurements to be a reliable means of predicting, before construction, whether a building will have a high radon level. Instead the EPA recommends that the radon levels be measured soon after the house is occupied.

Will increasing the ventilation in a house reduce the indoor radon concentration?

Increasing the ventilation at the ground floor level may reduce the indoor radon levels and this is effective up to about 400 becquerel per cubic metre (Bq/m3).  Other methods of radon reduction may be required for radon levels above this value.

Does radon affect only certain types of houses?

No. Radon is present in varying amounts in all types of houses, new or old, detached, semi-detached or terraced. You cannot make any confident prediction of your radon levels based upon the location, construction or age of your house. The RPII recommends that all householders, especially those living in High Radon Areas, should test for radon.

If my house is fitted with a radon barrier, can I be sure I won't have a radon problem?

No. Even if the radon barrier has been installed, it could have been damaged during the construction of the house. A single gap or hole in the barrier can make it ineffective. The only way of knowing is by testing your home for radon.

My house has a radon sump in the foundations so I do not have a radon problem.

No. Sumps that are installed at construction stage are stand-by (or inactive) radon sumps. Standby sumps cannot, and are not intended to, stop radon. They are a potential means of evacuating radon should the need arise. If, following a measurement, high radon levels are found the sump can be activated by adding a fan.

If I don't live in a High Radon Area, can I be sure I won't have a radon problem?

No. If you do not live in a High Radon Area, it simply means you have a lower chance of having a radon problem, it does not mean you won’t have a problem. Equally, living in a High Radon Area does not automatically mean that you will have a radon problem.

Will installing a radon sump disrupt my household and damage my floors?

No. If a radon sump is required, it will take approximately a day to install and all the excavation work is normally done from outside the house, with no disruption to the household. Installing a sump simply means removing the equivalent of a bucket full of soil or hard core from underneath the house and attaching a fan onto the pipe work which will link the sump itself to the outside.

Are children more at risk from radon than adults?

There is no conclusive scientific evidence that children are at greater risk from radon than adults.