DIY GUIDE · TRADES & CONSTRUCTION · CHECKED OCTOBER 2026
How to test your home for radon yourself
Fifteen minutes to set up and three months to wait. €40–€60 for a two-detector kit from a registered testing service.
Two detectors from a registered service, bedroom and living room, a metre up, three months, then post them back.
- Every step, start to finish
- Checked October 2026 — sources at the end
- Honest about when to call a pro
FIRST, THE HONEST ANSWER
Do it yourself, or get a builder?
Do it yourself if…
- You live in the home and can leave two small detectors untouched for at least three months
- You want to know your radon level before buying, selling, renovating or simply for your family's health
- You have finished major work on the house, such as new windows, an extension or insulation, and want to check the level again
- You can record the dates and the rooms carefully and post the detectors back on time
- You are content to wait for a laboratory report rather than a reading on the day
Get a pro if…
- Your test result is above the reference level of 200 Bq/m3 and the radon needs to be reduced
- You need a sump activated, a new sump dug, ventilation added or a membrane fitted
- You need a test result quickly for a house sale and cannot wait three months
- The building is a workplace, where the employer has a legal duty to test in High Radon Areas
- Your water comes from a private well or borehole and you want the water tested as well
Safety first
- Take radon seriously. The EPA ranks it second only to smoking as a cause of lung cancer, with around 350 cases a year in Ireland, and that the risk to a smoker is many times higher.
- Test while you live in the house normally; do not change how you heat or ventilate it to get a better number.
- Do not drill into floors, open up the floor slab or cut new vents yourself in response to a result. Reducing radon is building work, and done wrongly it can increase radon or damage the house.
- Keep the detectors away from children and pets; they are small and easily swallowed or chewed.
- If you work from home in a High Radon Area, know that the reference level for workplaces is 300 Bq/m3, and that the safety regulator and the EPA expect employers there to test.
- If your water comes from a private well, have it tested for radon as well as the air.
Stop here: Reducing radon: a sump, extra ventilation or a membrane
Reducing radon is building work: digging a sump under the floor slab and fitting a fan, cutting new vents through walls or floors, or fitting a membrane, all of which must suit the house and comply with the Building Regulations. The EPA publishes a list of registered radon remediation contractors, says an active sump typically costs about €1,200 and can range from €500 to €2,000, and offers a free test afterwards to check the work. A badly done fix can leave the risk in place. How to hire a radon specialist →
| MATERIAL | COVERAGE | FOR THIS JOB |
|---|---|---|
| Passive radon detectors | Two, from an EPA-registered testing service | One for the bedroom, one for the living room |
| Return envelope | Supplied with the kit | One |
| Placement record | Dates and rooms, on paper or online | One for each detector |
What the result means
36 m² of wall → 36 L for 2 coats. Buy about 36 L.
Home average = (bedroom result + living room result) ÷ 2, then the laboratory applies a seasonal adjustment for the months tested. If the bedroom reads 180 Bq/m3 and the living room 260 Bq/m3, the average is 440 ÷ 2 = 220 Bq/m3 before adjustment, which is above the 200 Bq/m3 reference level for homes.
The seasonal adjustment can move the figure up or down, because radon is usually higher in winter. The report gives the adjusted average; that is the number compared with the reference level, not either room on its own.
The EPA recommends a minimum measurement of three months, because radon levels swing from day to day, and only a result from at least three months can be compared with the national reference level. Buy the kit from one of the testing services on the EPA's register; they have met its criteria and must follow its measurement protocol. The kit contains two passive detectors that need no power.
A standard home test uses two detectors: one in the main bedroom and one in the living room, the rooms where your family spends most time. The registered service we read sells kits of 2 to 6 detectors depending on the size of the home. A large or split-level house may benefit from more.
A digital monitor gives a running reading and can be borrowed from participating libraries under the EPA's loan scheme. It is useful for seeing how levels change, but the EPA is clear that it cannot stand in for the three-month detector test.
Some services sell short-term kits for when time is tight, such as a house sale. A short test is an indication. The national reference level is set for long-term average exposure, and the EPA compares only tests of at least three months against it.
If your water comes from a private well or borehole, radon can also dissolve in it. The EPA recommends testing private groundwater supplies, and considers treatment where levels are above 500 Bq/l. Mains water from rivers and lakes carries very little radon.
THE PART THAT DECIDES THE FINISH
Before you start — your home and the rooms
The kind of home and its floors decide how you place the detectors and what the result means. Find your home below and do its list before opening the kit.
Any house, first test
The standard two-detector test.
- Check the EPA's radon map for your area
- Pick the bedroom used most, usually the main bedroom, and the living room
- Plan to test while the house is lived in normally; the EPA advises testing an occupied home
- Choose a start date when you will be home three months later to collect the detectors
A house built after 1 July 1998
Built under the building regulations that require radon protection.
- Look for a capped pipe outside or under the stairs: that is the standby radon sump
- Know that a standby sump without a fan does not reduce radon, as the EPA notes
- Test anyway; the protective measures are not a guarantee
- Keep a note of where the sump pipe is for the report
A house with suspended timber floors
Common in older homes; you will see airbricks low on the outside walls.
- Check the airbricks outside are clear of soil, leaves and plants as part of normal upkeep
- Place the detectors in the usual rooms, not in the void under the floor
- Note the floor type for the report
- Leave any changes to the vents until you have the result
An apartment or a room upstairs only
Radon comes from the ground, so ground-floor rooms are most at risk.
- In a ground-floor apartment, test as for a house
- In an upper-floor apartment the risk is usually lower, but a bedroom and living room test still gives an answer
- In a house where the bedrooms are upstairs, still put one detector in the main bedroom
- Mention the floor level of each room in the record
A home with a private well
Your water comes from your own well or a borehole.
- Ask the testing service whether it also tests water, or find a laboratory that does
- Test the air as normal; water and air are separate questions
- Do not leave a detector near a running shower or a kettle
- Keep the water result with the air report
THE JOB
How to test your home for radon
Check your area and order the kit
15 minutesLook up your home on the EPA's radon map. Order a home kit from one of the EPA's registered radon testing services; the EPA puts the cost at about €50, and between €40 and €60. Choose at least two detectors. Then go to the section above and do the list for your home.
- Order from a registered service so the result is valid
- Ask whether the price includes return postage and the report
- Leave the detectors sealed until the start date
Mistake to avoid: Buying a cheap detector online from an unregistered seller. The result may not be comparable with the national reference level.
Choose the two rooms and the spots
10 minutesPick the main bedroom in regular use and the living room. In each, find a spot at least a metre above the floor, such as a dressing table, bedside locker or coffee table, as the EPA's measurement protocol suggests. Keep away from window sills, radiators, fireplaces and televisions, and do not put the detector inside a drawer, cupboard or anything else.
- A shelf in the middle of the room is better than one by a window
- Pick a spot where children and pets will not move it
- Avoid the kitchen and the bathroom; they are not where the protocol tests
Mistake to avoid: Putting the detector on a windowsill. Fresh air from the window gives a reading lower than the room's real level.
Open the detectors and record the start
5 minutesOn the start date, open each detector's packaging as the kit's instructions say. Write down the date, the room and the exact spot for each detector, together with its serial number. If the service uses an online account, enter the start date and the locations there on the same day, as the registered service we read asks.
- Match each serial number to its room
- Photograph each detector in place for your record
- Keep the packaging and the return envelope safe
Mistake to avoid: Forgetting to record the start date. Without it, the laboratory cannot calculate the result.
Place the bedroom detector
2 minutesSet the first detector in the spot you chose in the main bedroom, at least a metre above the floor and in the open air of the room. Leave it upright and uncovered. Tell everyone in the house what it is and that it must not be moved.
- Do not cover it with clothes or papers
- Keep it away from heaters and electric blankets
- Leave it in the same place for the whole test
Mistake to avoid: Moving the detector during cleaning and putting it somewhere else. The result no longer represents the room.
Place the living room detector
2 minutesSet the second detector in the living room in the same way: open air, at least a metre up, away from windows, radiators, the fireplace and the television. If you have a stove, keep the detector well away from it.
- Place it where people sit for long periods
- Use the same height as the bedroom detector if you can
- Check it is not behind a curtain
Mistake to avoid: Leaving it on the mantelpiece. Heat and the draught of the chimney change the air around it.
Live normally for at least three months
3 monthsLeave the detectors where they are for at least three months and no more than twelve, as the EPA's protocol sets. Live in the house as you usually do: heat it, open windows and use the rooms as normal. A test taken over winter will usually read higher, which the laboratory allows for with its seasonal adjustment.
- Do not open more windows than usual to lower the result
- If the house will be empty for weeks, note the dates
- Keep the return envelope with your notes
Mistake to avoid: Changing how you ventilate the house during the test. The result then does not show the radon you normally breathe.
Collect the detectors and post them back
10 minutesOn the end date, collect both detectors, seal them in their packaging as the instructions say, and write down the end date. Enter it in the online account if there is one. Post them back to the laboratory the same day.
- Post them promptly; a delay can affect the result
- Keep a copy of your record of dates and rooms
- Note the date you posted them
Mistake to avoid: Leaving the detectors in a drawer for weeks after the end date. They keep measuring, and the dates no longer match.
Read your report
15 minutesThe registered service we read uploads its report within 1-2 weeks of receiving the detectors. Read the seasonally adjusted average for the home and compare it with the reference level of 200 Bq/m3. The EPA gives the average for Irish homes as 77 Bq/m3, which helps put your number in context.
- Look at both rooms as well as the average
- Keep the report with the house's documents; a buyer may ask for it
- Ring the testing service if anything is unclear
Mistake to avoid: Comparing one room's raw reading with the reference level. It is the seasonally adjusted average that counts.
Decide what comes next
15 minutesIf the result is below 200 Bq/m3, the EPA says no further action is needed unless you carry out major work that could change how radon enters or leaves the house, such as new windows, an extension or insulation; test again after any of those. If it is above 200 Bq/m3, the radon needs to be reduced, which is where this guide stops. Contact one of the EPA's registered radon remediation contractors.
- Test again after major refurbishment, even with a low first result
- Ask more than one remediation contractor for advice
- Keep your first report; the contractor will want it
Mistake to avoid: Ignoring a high result because the house feels well ventilated. Radon gives no sign; only the measurement tells you.
After any fix, test again
15 minutesOnce radon reduction work is finished, test again to check it worked. The EPA offers a free post-remediation test for homes. If the levels were high and you have had remediation, the EPA advises retesting every 5 years to check they stay low.
- Request the free post-remediation test from the EPA
- Put the five-year retest date in your calendar
- Keep the contractor's paperwork with both reports
Mistake to avoid: Assuming the fix worked. Most remediation succeeds first time, but the EPA says there is no absolute certainty without a retest.
The mistakes that show
- Testing for less than three months and comparing the result with the reference level
- Placing detectors on windowsills, beside radiators or inside a cupboard
- Forgetting to record the start and end dates
- Using a digital monitor instead of a laboratory test
- Relying on a neighbour's result
- Not testing again after new windows, an extension or insulation
Stop here and get a radon remediation contractor
- Your seasonally adjusted average is above 200 Bq/m3
- A standby sump needs a fan fitted, or a new sump is needed
- You are thinking of new wall vents, sub-floor ventilation, a positive input ventilation unit or a membrane
- The result is very high and you want advice on the right fix
| WHAT YOU SEE | WHY, AND THE FIX |
|---|---|
| My result is just above 200 Bq/m3 | The radon still needs reducing. The EPA says moderate levels can often be lowered with improved ventilation, and that any significant reduction lowers your risk. Talk to a registered remediation contractor about the simplest option. |
| The two rooms gave very different readings | Normal; radon varies from room to room, and ground-floor rooms are often higher. The report's average is what is compared with the reference level. |
| A detector was moved or lost during the test | Tell the testing service. A moved detector can still give a result if you know where it was and when; a lost one means a retest of that room. |
| My digital monitor reads differently from the lab report | Digital monitors give an indication over a short time. The EPA treats a monitor as a guide only and the three-month detector test as the answer; trust the laboratory result. |
| My neighbour's result was low, so I did not test | The EPA says a neighbour's result is no guide to yours. Radon varies from house to house even on the same street. |
| The house was empty for part of the test | An unoccupied home usually reads higher, because fewer doors and windows are opened. Tell the testing service; the EPA recommends testing an occupied home. |
| I have a standby sump, so I assumed I was safe | A standby sump without a fan does not reduce radon, as the EPA notes. Test, and if the result is high a contractor can activate the sump. |
| My result was high after I fitted new windows | Better-sealed windows can raise radon by reducing ventilation. The EPA advises testing after major work such as new windows, an extension or insulation; a high result needs remediation. |
WHAT YOU SAVE
What it costs to do it yourself
| Two-detector home test kit with analysis | €40–€60 |
|---|---|
| Detector from one registered service, each | from €29 |
| Digital monitor on library loan | Free where the library takes part |
| Total | €40–€60 |
| DIY total | €40–€60 |
Guide prices compiled by the Locufy team from published Irish and UK provider price lists and 2026/27 cost guides. Updated 2026.
Kit prices from the EPA's guidance and a registered testing service, October 2026. If the result is high, remediation is a separate cost: the EPA puts an active sump at about €1,200, activating a standby sump at about €1,000, and improved ventilation at a few hundred euro. The professional price, from the price guide, is shown alongside and covers testing through to remediation.
RATHER NOT?
Radon specialists near you, with prices shown
The ones who cover your area, nearest first, with one score from every review. No account needed to look.
Or post the job free and let them come to you.
File the report with the house's documents. A buyer, a lender or a future contractor may ask for it.
New windows, an extension or insulation can change how radon enters and leaves the house. The EPA advises testing again after any of them, even if your first result was low.
Passive detectors go back to the laboratory in their envelope, so there is nothing to throw away. A digital radon monitor you own is electrical waste: when it reaches the end of its life, take it to a WEEE drop-off point or a civic amenity site listed on mywaste.ie, or back to a shop that takes old electrical items. Return a library monitor to the library.
Book the EPA's free post-remediation test, keep the fan running if you have one, and test again every 5 years.
Testing your home for radon: questions people ask
Buy a kit from one of the EPA's registered radon testing services, put one detector in the main bedroom and one in the living room, at least a metre above the floor, for at least three months, then post them back for analysis.
The national reference level for homes is 200 Bq/m3. Above it, the EPA says the radon should be reduced. There is no level with no risk, and any reduction helps.
At least three months, as the EPA recommends, because radon levels vary a lot from day to day. Only a test of three months or more can be compared with the reference level.
It gives a useful indication, but the EPA does not accept it in place of three months with detectors from a registered service.
No. The EPA says there is no grant to cover the cost of radon remediation, but it offers a free test afterwards to check the work.
The Locufy price guide for Ireland puts radon testing and mitigation at €50–€2,000 per job, with €400 typical: a test kit at the low end, an active sump at the high end.
MORE GUIDES
More DIY guides
Sources — checked October 2026
- Radonova — Radtrak³ home radon testing kit: from €29; 2–6 detectors; living room and master bedroom; 90 to 365 days; report within 1-2 weeks; EPA-validated, ISO 17025 laboratory
- EPA — radon testing: kit about €50, €40 to €60; two detectors in the living room and main bedroom for three months; digital monitor not a replacement; above 200 Bq/m3 remediate and retest, free post-remediation test, retest every 5 years; below 200 Bq/m3 retest after major work; workplaces 300 Bq/m3
- EPA — Measurement Protocol for homes and workplaces: detectors at least one metre above the floor; avoid window sills, radiators, fireplaces, televisions and placing inside objects; 3 to 12 months; record dates and locations; seasonal adjustment
- EPA — radon: about 350 lung cancer cases a year; High Radon Areas; reference level 200 Bq/m3; minimum three-month test; neighbour's result no guide; library loan scheme; no remediation grant
- EPA — radon FAQs: occupied homes; no grant for remediation; seasonally corrected average
- EPA — fixing a radon problem: standby sumps since 1 July 1998; ventilation up to 50%; active sump about €1,200, €500 to €2,000; activating a standby sump about €1,000; registered remediation contractors; free post-remediation test
- EPA — householders: average radon in Irish homes 77 Bq/m3; radon in private well water, 500 Bq/l
- HSA — radon in workplaces: employers in High Radon Areas must test; reference level 300 Bq/m3
- MyWaste — electrical items: anything with a plug or battery to a WEEE drop-off point or civic amenity site