Damp and Mould in UK Homes: What the Numbers Tell Us

Condensation and mould were the most frequently recorded forms of significant damp in English homes during 2024. Approximately 3% of dwellings were affected by serious condensation or mould, compared with 2% for penetrating damp and around 1% for rising damp when the figures were rounded.

This matters because rising damp is often the first conclusion reached when moisture appears near the bottom of a wall. The national data shows that serious condensation is considerably more common, while penetrating damp is also recorded more frequently.

The figures do not establish what is happening within an individual property. They do demonstrate why the moisture pattern and surrounding building conditions should be investigated before a damp-proof course or any other work is proposed.

Significant damp was most frequently identified within the private rented sector. In 2024, approximately 10% of privately rented dwellings had a damp problem, compared with 7% of socially rented homes and 4% of owner-occupied properties.

Within social housing, local authority homes had a slightly higher recorded rate than housing association properties. Damp affected approximately 8% of local authority dwellings and 6% of housing association homes.

These differences can reflect property condition, maintenance, ventilation, heating affordability and the characteristics of the housing stock. Tenure alone does not identify the cause of damp within a particular home.

Around 30% of households said that their home had experienced condensation, damp or mould. Physical housing surveys recorded a significant damp problem in approximately 5% of dwellings.

The difference does not mean that occupants are imagining the problem. The two figures measure different things. Household reports can include minor condensation, intermittent mould, seasonal moisture and problems in rooms that were unaffected on the day of the physical inspection.

The physical survey figure only includes damp considered significant enough to form part of the formal housing assessment. Problems that are limited, temporary or concealed may not meet that threshold.

The same pattern can be seen across every tenure:

The proportion of English dwellings assessed as having a significant damp problem increased from approximately 4% in 2019 to 5% in 2024.

Over the same period, serious condensation and mould increased from around 2% to 3%, while penetrating damp increased from approximately 1% to 2%. Rising damp rose from 1.0% to approximately 1.5%.

The English Housing Survey identifies several factors that may have contributed to the increase. These include delayed maintenance during the pandemic, inadequate ventilation and difficulty keeping homes consistently warm as energy costs increased.

The figures do not suggest that one defect is responsible for every increase. Damp develops through different combinations of moisture, property condition, ventilation, temperature and occupancy.

In 2023–24, approximately 1.3 million households were living in homes assessed as damp. More than 600,000 of those households included at least one person with a long-term physical or mental health condition.

The proportion of damp households containing somebody with a health condition increased from approximately 33% in 2013–14 to 47% in 2023–24. However, the English Housing Survey also recorded an increase in health conditions among households living in homes without damp.

These figures show that poor housing conditions and existing health needs frequently overlap. They do not prove that damp caused every condition recorded within those households.

Where mould or damp is affecting somebody with breathing difficulties, reduced immunity or another health concern, medical advice should be sought alongside investigation of the property.

National figures are useful for understanding the scale of the problem, but they cannot explain why one particular wall is wet or why mould has developed within an individual home.

A patch of moisture may be caused by condensation, rainwater penetration, defective plumbing, moisture at ground level or a combination of factors. Similar-looking symptoms can have very different causes.

Property age and tenure are not enough to make a reliable diagnosis either. An older owner-occupied home may be completely dry, while a recently built property can experience severe condensation if moisture, ventilation and temperature are poorly balanced.

The cause must be established from the moisture pattern, construction, environmental conditions and defects present at the property.

A damp survey examines the areas of concern and the wider conditions that may be contributing to them. The inspection can include moisture patterns, internal humidity, ventilation, external defects, rainwater goods, plumbing risks and the construction of the affected walls and floors.

Professional moisture meters and hygrometers may be used where appropriate, but individual readings are not treated as a diagnosis. The results must be interpreted alongside the visible evidence and how the building is constructed.

The purpose of the survey is to identify the cause best supported by the evidence, establish the visible extent of the problem and explain what further investigation or work may be required.

Following the inspection, you will receive a written report setting out the findings and recommendations in clear language.