Home ventilation statistics show how ventilation relates to housing quality, damp, household behavior and indoor air. The figures below cover England, selected English new developments and selected recently built homes in the southeastern United States, with periods and definitions kept explicit.
Key Home Ventilation Statistics
The most useful headline figures are:
- In 2023, 236,000 English dwellings, or 0.9% of the housing stock, had inadequate ventilation in the English Housing Survey assessment.
- In 2023–24, more than 60% of inadequately ventilated English dwellings had a damp problem.
- In 2023–24, only 5% of adequately ventilated English dwellings had a damp problem.
- In 2023–24, 142,000 English dwellings with inadequate ventilation had damp.
- In 2023–24, inadequate ventilation affected 2% of private rented dwellings in England.
- In 2023, inadequate ventilation affected 0.3% of local-authority rented dwellings in England.
- In 2023, inadequate ventilation affected 0.9% of housing-association dwellings in England.
- In 2019, around 2.4 million English dwellings, or 10%, had trickle vents in all surveyed rooms.
- In 2024–25, 1.4 million English households, or 6%, had damp problems present.
- In 2024–25, 83% of English households reporting damp said they opened windows to address damp or condensation.
- In 2024–25, 42% of English households reporting damp said they used extractor fans.
- In 2024–25, 11% of private-renter households in England had damp, compared with 4% of owner-occupier households.
- Among English households reporting bathroom damp or mould, about 60% opened a window or used an extractor fan every day during the Energy Follow Up Survey period.
- Among English households reporting bedroom damp or mould, 35% opened the bedroom window daily in winter during the Energy Follow Up Survey period.
- In the selected English new-home study, only one of 25 System 3 homes fully met the study guidance for minimum extract airflow and trickle-ventilation provisions.
- In the selected English new-home study, one Didcot home had extract flow about 60% below the recommended whole-dwelling rate at normal trickle speed.
- The U.S. Department of Energy study monitored 51 recently built homes in Florida, Georgia and South Carolina for one to two weeks.
- In that selected U.S. study, properly working whole-house mechanical ventilation reduced carbon dioxide concentration by 30%.
Contents
- How common inadequate home ventilation is
- Home ventilation data on damp and housing quality
- Home ventilation by tenure and household behavior
- New-build ventilation compliance and airflow
- Bedroom, bathroom and kitchen ventilation trends
- Measured ventilation outcomes for indoor pollutants
How Common Inadequate Home Ventilation Is
The English Housing Survey defines inadequate ventilation through inadequate room ventilation or inadequate appliance ventilation. That measure is not the same as a measured air-change rate or a count of homes with mechanical ventilation installed.
In 2023, the survey assessed 236,000 English dwellings, equivalent to 0.9% of the stock, as having inadequate ventilation. The 2023–24 housing-quality analysis presented the estimate as 1%, also corresponding to 236,000 dwellings; that rounded presentation combines two survey years. English Housing Survey 2023 to 2024: drivers and impacts of housing quality
Earlier figures should not be treated as directly interchangeable with the later combined-year estimate:
- In 2019, around 145,000 English dwellings, or about 1%, lacked adequate room or appliance ventilation.
- In 2019, around 2.4 million dwellings, or 10%, had trickle vents present in all surveyed rooms.
- Among dwellings built after 1990, 18% had trickle vents in all windows in 2019, compared with 3% of dwellings built before 1919.
The presence of trickle vents indicates equipment presence, not necessarily effective airflow. The 2019 figures come from an earlier English Housing Survey energy report and use a different measurement context from the 2023–24 assessment.
Home Ventilation Data on Damp and Housing Quality
Ventilation status and damp were strongly associated in the 2023–24 English Housing Survey, but the survey results are not causal estimates. Damp was assessed in the same housing-quality survey.
| English dwelling group, 2023–24 | Dwellings with damp |
|---|---|
| Inadequately ventilated dwellings | More than 60%; 142,000 dwellings |
| Adequately ventilated dwellings | 5% |
| Inadequately ventilated private rented dwellings | 76% |
| Adequately ventilated private rented dwellings | 8% |
| Inadequately ventilated housing-association dwellings | 59% |
| Adequately ventilated housing-association dwellings | 7% |
| Inadequately ventilated owner-occupied dwellings | 42% |
| Adequately ventilated owner-occupied dwellings | 3% |
The tenure-specific comparisons show why ventilation and housing condition should be read together. They describe associations within the survey, not controlled comparisons that isolate ventilation from building condition, occupancy or other factors. English Housing Survey 2023 to 2024: drivers and impacts of housing quality
The survey also reported that severe condensation and mould affected 3% of English homes in 2014 and 20% of dwellings with inadequate room ventilation in that earlier survey. That older room-ventilation measure is narrower and should not be merged with the later inadequate-ventilation definition.
Related housing-condition figures provide context but are not ventilation measures. In 2023–24, uninsulated walls were present in 47% of English housing, or 11.9 million dwellings, and 8% of those dwellings had damp, equal to 909,000 dwellings.
Home Ventilation Statistics by Tenure and Household Behavior
Ventilation-related equipment and actions differ by tenure, while the survey questions often allow multiple responses. The following 2023 figures describe assessed dwelling conditions, whereas the 2024–25 figures describe household-reported responses to damp or condensation.
| English tenure group | Inadequate ventilation, 2023 | Damp present, 2024–25 |
|---|---|---|
| Private rented | 2% | 11% |
| Local-authority rented | 0.3% | 9% |
| Housing association | 0.9% | 6% |
| Owner occupied | Not supplied | 4% |
In 2024–25, 1.4 million households, or 6% of English households, had damp problems present. Damp prevalence was 8% among households with dependent children, compared with 5% among households without dependent children. English Housing Survey 2024 to 2025: perceptions and impacts of housing quality
Among households reporting damp, the most commonly reported response was opening windows:
- 83% opened windows, 42% used extractor fans, 20% used trickle vents and 12% used none of the listed damp-removal methods in 2024–25.
- Window opening was reported by 84% to 86% of renters reporting damp, compared with 80% of owner occupiers.
- Extractor-fan use was 51% for housing-association renters, 47% for local-authority renters, 41% for private renters and 39% for owner occupiers.
- Trickle-vent use was 31% for local-authority renters, 27% for housing-association renters, 20% for owner occupiers and 14% for private renters.
These are self-reported, multiple-response results among households reporting damp; they measure reported actions, not verified airflow or the effectiveness of each method.
New-Build Home Ventilation Compliance and Airflow
A government study of selected English new developments examined ventilation through walkthroughs and monitoring rather than a national housing survey. Eighty homes participated in walkthrough inspections, 54 had limited monitoring and 10 had detailed monitoring; the sample was not nationally representative. Ventilation and Indoor Air Quality in New Homes
For System 1 extract fans, compliance varied across five listed developments:
| Room | Compliance range across five developments |
|---|---|
| Kitchen | 0%–67% |
| Bathroom | 13%–65% |
| WC | 38%–100% |
For System 3 extract fans, compliance also varied by development:
| Development | Kitchen | Bathroom | WC |
|---|---|---|---|
| Bolton | 57% | 79% | 100% |
| Didcot | 40% | 80% | 100% |
| Manchester | 0% | 0% | 0% |
The study used Approved Document F thresholds and measured room or system conditions, with small development-level samples. It therefore illustrates variation in selected developments rather than the performance of all English new homes.
Reported use was also uneven. Among 56 System 1 homes, 32 occupants always used the extract fan when cooking, 15 sometimes did and 8 never did; the report summarized 85% as sometimes or always using the fan.
When showering, 47 always used it, 4 sometimes did and 4 never did, with one fan reported not to be working properly.
Measured trickle-speed airflow showed the scale of some case-study shortfalls: one Didcot home was about 60% below the recommended whole-dwelling rate, two Bolton homes were 78% and 87% below, and Manchester limited-monitoring homes were 56% to 85% below the minimum recommended rate. Only one of 25 System 3 homes visited fully met the study guidance for both minimum extract airflow and trickle-ventilation provisions.
Home Ventilation Trends in Bedrooms, Bathrooms and Kitchens
The Energy Follow Up Survey provides household-reported evidence for rooms where moisture and ventilation behavior matter. Its period is the survey period reported in the 2021 report, so these figures should not be treated as direct updates to the 2024–25 English Housing Survey. Energy Follow Up Survey: thermal comfort, damp and ventilation
Among 2.6 million households reporting damp or mould in a bathroom with a WC, about 60% opened a window or used an extractor fan every day. Thirteen percent never used ventilation or had no window or extractor fan.
Among 3.3 million households reporting bedroom damp or mould, 35% opened the bedroom window daily in winter, while 19% never opened the bedroom window or had no window or extractor fan.
The survey did not establish a statistically significant difference in damp or mould prevalence for several reported behaviors:
- Damp or mould was reported by 25% of households airing the house every day or most days in winter, versus 29% airing it occasionally, rarely or never.
- Damp or mould was reported by 27% of households using a bathroom window or extractor fan, versus 28% never using one or lacking one.
- Damp or mould was reported by 29% of households always or mostly drying clothes indoors in winter, versus 28% doing so occasionally, rarely or never.
These findings are behavior associations and should not be interpreted as causal effects of opening windows, using fans or drying clothes indoors.
Measured Home Ventilation Outcomes for Indoor Pollutants
The Energy Follow Up Survey also asked households reporting damp or mould about perceived health effects. Among 6.5 million households reporting damp or mould, 36%, or 2.3 million households, said a medical condition was made worse by damp; this was self-reported and was not a clinical diagnosis.
Within those responses, 24% reported a respiratory condition made worse by damp, 13% reported a skin condition and 7% reported allergies. These categories describe reported attribution among households with damp or mould, not measured population health effects. Energy Follow Up Survey: thermal comfort, damp and ventilation
A separate U.S. Department of Energy study monitored 51 recently built homes in Florida, Georgia and South Carolina for one to two weeks. It examined selected southeastern states and properly working whole-house mechanical systems, so it is not a national U.S. adoption estimate. Ventilation and Indoor Air Quality in Recently Constructed U.S. Homes: Measured Data from Select Southeastern States
In that selected study, properly working whole-house mechanical ventilation produced these measured pollutant changes:
| Outcome | Reported change |
|---|---|
| Carbon dioxide concentration | 30% reduction |
| Radon and nitrogen dioxide levels | 42% reduction |
| Formaldehyde concentration | 7% reduction |
The English new-home study found that none of its detailed-monitoring homes exceeded the WHO 30-minute formaldehyde guideline on a weekly-average basis. Because monitoring used seven-day averages, however, it could not determine whether any individual 30-minute period exceeded the guideline. Ventilation and Indoor Air Quality in New Homes