Indoor Air Quality Statistics Ireland 2026: Ventilation, Radon, Carbon Monoxide and Damp

Last updated: September 2026. Human written and fact checked against each named source.

Ireland’s outdoor air is among the cleanest in Europe, yet monitoring inside new, A rated Irish homes found carbon dioxide above recommended levels for 94% of winter sleeping hours and ventilation rates consistently below recommended levels. This page gathers the current indoor air quality and ventilation figures for Ireland in one place: what has been measured inside Irish homes, how outdoor air compares with the rest of Europe, and the numbers on radon, carbon monoxide, damp and asthma. Every figure links to the EPA, CSO, Eurostat, SEAI or research source it came from, and the page is written for journalists, researchers, housing professionals and homeowners who need a number they can cite. It sits alongside our damp and mould statistics and heat pump statistics.

Key Indoor Air Quality Statistics for Ireland at a Glance

• Carbon dioxide exceeded 1,000 ppm during 94% of winter sleeping hours in nine monitored energy efficient Irish homes. Source: Public Policy, Indoor Air Quality and Ventilation in Newly Built Homes, September 2025
• Fine particulate matter exceeded the World Health Organization 24 hour guideline in 92% of winter kitchen measurements in the same homes, all of which cooked with electricity. Source: Public Policy, September 2025
• Mean ventilation rates in those homes were 0.28 air changes an hour across the year and 0.21 in winter, consistently below recommended levels. Source: Public Policy, September 2025
• Around 1,700 premature deaths occur in Ireland each year because of poor air quality. Source: EPA, Air Quality in Ireland 2024
• Only 7.5% of people in Ireland report pollution, grime or other environmental problems where they live, against an EU average of 12.2%. Source: Eurostat ilc_mddw02
• About 350 cases of lung cancer in Ireland every year can be linked to radon, which accounts for about 60% of the total radiation people here are exposed to. Source: EPA, radon health risks
• Only 11% of Irish households have been tested for radon, and 9% of those tested were above the reference level. Source: CSO, Household Environmental Behaviours 2024
• Carbon monoxide kills on average six people in Ireland every year. Source: Gas Networks Ireland
• 21.2% of people in Ireland live in a home with leaks, damp or rot, the fourth highest rate in the EU. Source: Eurostat ilc_mdho01
• The health cost of indoor air pollution in Ireland is estimated at €0.15 billion a year, or 0.06% of GDP. Source: Public Policy, September 2025

What Monitoring Inside New Irish Homes Found

Ireland has no national survey of indoor air, so the best evidence is research monitoring. The most recent is the ALIVE project, summarised in a Public Policy paper published on 18 September 2025, which placed sensors in naturally ventilated, airtight, A rated dwellings and recorded conditions across the seasons, per Public Policy’s Indoor Air Quality and Ventilation in Newly Built Homes. The sample is small, nine dwellings, so the figures describe those homes rather than the national stock. They are still the clearest published picture of what happens inside a modern Irish home built to current standards.

Two details matter for reading the table. The particulate readings came from homes cooking with electricity, and the paper notes that gas cooking could make them worse. And the carbon dioxide finding is a winter one: occupants open windows less in cold weather, so a home that relies on people opening windows is least ventilated exactly when it is most sealed.

Why Newer Homes Are the Ones Affected

Airtightness is what makes a modern home cheap to heat, and it is also what removes the accidental ventilation older homes had through gaps and chimneys. The number of homes in that position is growing quickly. The CSO’s BER register holds 146,902 rated dwellings built since 2020 (calculated by adding the 2020 to 2024 and 2025 to 2029 cohorts), more than 99% of them rated A or A0, per the CSO Domestic Building Energy Ratings Q2 2026. Retrofits add to the total: our SEAI grant statistics show 58,600 homes upgraded with grant support in 2025.

The SEAI’s own guidance is direct on the point. A well insulated home is warmer and more airtight, which makes good ventilation important for both the building and its occupants, and mechanical ventilation should be used in very airtight homes, per the SEAI ventilation systems guide. It adds that mechanical systems can be more energy efficient than natural ventilation because they give more control and limit heat loss, and that all wet rooms should have a mechanical extract fan. The Public Policy paper reaches the same place from the evidence, recommending hybrid or mechanical ventilation where natural ventilation is likely to fall short, and noting that the recast EU buildings directive requires member states to set indoor environmental quality requirements for new and existing homes.

Outdoor Air: Clean by European Standards, Still Costly

What comes in through the vents matters too. Ireland met all EU legal air quality standards in 2024, and the European Environment Agency describes Irish air quality as one of the best in Europe, per the EEA’s Europe’s Environment 2025. People notice: only 7.5% of people in Ireland report pollution, grime or other environmental problems in their area, against an EU average of 12.2%, the sixth lowest rate in the EU (ranking calculated from the country list), per Eurostat ilc_mddw02 for 2023. The table shows a selection of member states from that dataset.

The trend runs the wrong way, though. The Irish figure was 4.0% in 2011 and has nearly doubled since, while the EU average fell from 15.6% to 12.2% over the same period. And clean by European standards is not the same as harmless. The EPA reports around 1,700 premature deaths in Ireland each year because of poor air quality, names solid fuel burning and traffic as the primary sources, and projects that Ireland will reach only 93% compliance for fine particulates and 78% for nitrogen dioxide against the stricter EU limits that apply from 2030, per the EPA’s Air Quality in Ireland 2024 release, which draws on a network of 115 monitoring stations. Solid fuel is still the main space heating fuel in 4% of rated Irish homes, per the CSO BER release.

Radon: The Largest Radiation Risk in Irish Homes

Radon is a radioactive gas that rises from the ground and collects indoors. The EPA states that the greatest health risk from radiation in Ireland is from radon, that it accounts for about 60% of the total radiation people here are exposed to, and that about 350 cases of lung cancer every year can be linked to it. The risk is 25 times greater for smokers than for lifelong non-smokers exposed to the same level, per the EPA radon health risks page.

Testing is rare. The CSO found that 11% of households had been tested for radon, and that 9% of those tested were above the reference level of 200 Bq/m³. One in five households in the West region had tested, against fewer than one in twenty (4%) in Dublin, and nearly one in four (24%) of tested households in the Border region were above the reference level, per the CSO Household Environmental Behaviours 2024 release of July 2025. Put together, those figures mean roughly one household in a hundred knows it has a radon problem (calculated), and the true number with one is unknown because nine in ten have never tested.

Carbon Monoxide

Carbon monoxide is produced when any fossil fuel burns without enough air, which makes it a ventilation problem as much as an appliance one. It kills on average six people in Ireland every year, per Gas Networks Ireland. The SEAI’s guidance is that permanent ventilation is required to supply air to any open flued appliance such as a stove, gas fire or open fire, per its ventilation systems guide. The awareness research we could find is dated: a nationally representative survey of 1,000 adults in August 2014 found that 55% of Irish households had no carbon monoxide alarm and that one in five had not had their boiler serviced in two years or longer, per the NSAI.

In rented homes ventilation is a legal requirement: 60.5% of private rented dwellings inspected in 2025 failed the minimum standards on first inspection, per our rental housing standards statistics for Ireland.

Moisture, Mould and Asthma

Moisture is the most visible indoor air problem. Eurostat records 21.2% of people in Ireland living in a dwelling with a leaking roof, damp walls or rot in 2023, the fourth highest rate in the EU, per Eurostat ilc_mdho01. The SEAI notes that warm indoor air carries more water vapour than cold outdoor air, that cooking, laundry and showers add to it, and that good ventilation improves indoor air quality by removing stale air, moisture and harmful pollutants, per its ventilation guide.

The health stakes are high here because of how common respiratory illness is. Some 450,000 people in Ireland currently have asthma, and one person on average dies from it every five days, per the Asthma Society of Ireland. The Public Policy paper links fine particulates to asthma, chronic obstructive pulmonary disease and cardiovascular events, and puts the health cost of indoor air pollution in Ireland at €0.15 billion a year. Our damp and mould statistics cover the moisture side in full.

What the Rules Require

Ventilation is a legal requirement in two places. For rented homes, the Housing (Standards for Rented Houses) Regulations 2019 list ventilation among the minimum standards, and 38,765 of the 64,120 private rented dwellings inspected by local authorities in 2025 failed to meet those standards overall, a rate of 60.5% (calculated), per the Department of Housing’s rental inspections data. The inspections test every standard, so that figure is not a count of ventilation failures alone.

For new and upgraded homes, Part F of the Building Regulations governs ventilation, including a minimum kitchen extraction rate of 30 litres a second cited in the Public Policy paper, which argues that extraction should be checked over time and not only at handover, and that current energy rating assessments do not account for how occupants actually ventilate.