Under the Housing Health and Safety Rating System (HHSRS), damp and mould is the first of the listed hazards that councils use to judge whether a home is safe. HHSRS damp and mould assessments look at how likely it is that someone will be harmed over the next 12 months and how serious that harm could be. A high score makes it a Category 1 hazard, which the council must act on. This guide explains how the system works, what changed in June 2026 and how it links to Awaab’s Law.
This is general information, not legal advice.
What is the HHSRS?
The HHSRS is a risk assessment tool set up under Part 1 of the Housing Act 2004. The government describes it as a tool used to identify and assess risks to the health and wellbeing of people in their own home, whether rented or owned. It applies in England and is used mainly by local councils to decide whether to take enforcement action against landlords.
The HHSRS does not set fixed standards such as a maximum moisture reading. Instead, it asks whether a defect in the home creates a risk of harm and how serious that risk is.
The 2026 changes
The HHSRS was revised for the first time in around 20 years. The Housing Health and Safety Rating System (England) (Amendment) Regulations 2026 came into force on 23 June 2026 and apply to inspections started on or after 22 June 2026. The main changes are:
- the number of hazards reduced from 29 to 21 by combining similar hazards, for example a single “falls on the level” hazard and a combined “fire and explosions” hazard
- a simpler scoring method
- three bands (High, Medium and Low) in place of the previous ten bands (A to J)
Damp and mould remains hazard 1 in the list, alongside related hazards such as excess cold (hazard 2), which often goes hand in hand with condensation and mould.
The damp and mould hazard
The HHSRS regulations define the damp and mould growth hazard as “exposure to house dust mites, damp, mould or fungal growths”. This wording was not changed by the 2026 amendments.
Health risks
The government’s guidance on the health risks of damp and mould explains that the main effects are respiratory: cough, wheeze and shortness of breath, airway infections, and the development or worsening of asthma. Damp and mould can also affect the skin and eyes and cause stress and anxiety.
People at increased risk include those with asthma, COPD or other lung conditions, people with weakened immune systems, pregnant women and new mothers, children and young people, older people, those who are bedbound or housebound, and people with mental health conditions.
Common causes
Damp and mould hazards usually come from one or more of:
- condensation, where warm moist air meets cold surfaces (see relative humidity and condensation)
- penetrating damp from defective roofs, walls, gutters, windows or pipework
- rising damp from ground moisture
- inadequate ventilation, heating or insulation
The same guidance is clear that the fundamental causes are usually building deficiencies, inadequate ventilation or heating, or poor energy efficiency, not tenants’ normal domestic activities. Our guide to types of damp explains how to tell them apart.
How HHSRS hazards are assessed
The government’s HHSRS landlord and agent guide, updated in September 2026, sets out the process.
Step 1: Inspect and identify deficiencies
The assessment starts with a full inspection of the property, including any garden, yard or outbuildings. The assessor records deficiencies, such as a leaking gutter, a missing extract fan or a cold external wall with mould growth.
Step 2: Link deficiencies to hazards
Each deficiency is linked to the hazard it contributes to. A damp, mouldy bedroom is assessed under damp and mould. A poorly heated, uninsulated home may also be assessed under excess cold.
Step 3: Assess the likelihood of harm
The assessor judges the likelihood of harm requiring medical intervention over the next 12 months. This is judged for the most vulnerable age group for that hazard, not the people who actually live there. So a home can score highly even if it is currently occupied by healthy adults.
Step 4: Assess the spread of harm
The assessor considers how serious the harm could be, using four classes:
| Class of harm | Examples from government guidance |
|---|---|
| Moderate | Broken finger, slight concussion, regular serious coughs or colds |
| Serious | Sleep disturbance, chronic severe stress, mild heart attack |
| Severe | Asthma, mild stroke, serious fracture |
| Extreme | Lung cancer, paralysis below the neck, death |
For damp and mould, respiratory effects such as asthma are particularly relevant.
Step 5: Calculate the hazard score
Likelihood and severity are combined in a formula to produce a hazard score, which falls into a band.
| Score | Band | Category |
|---|---|---|
| 1,000 or more | High | Category 1 |
| Over 100 and under 1,000 | Medium | Category 2 |
| 100 or below | Low | Category 2 |
Category 1 vs Category 2 hazards
Category 1 hazards are the most serious. Where a council finds one, it has a duty to take action.
Category 2 hazards are less serious. The council has a power, but not a duty, to take action.
Social housing must also meet the Decent Homes Standard, which requires homes to be free of Category 1 hazards.
How councils enforce HHSRS damp and mould hazards
If a council identifies a hazard, it can choose from several enforcement options, set out in the government guide:
- Hazard awareness notice – tells the landlord about the hazard without requiring works
- Improvement notice – requires the landlord to carry out specified works within a set time
- Prohibition order – restricts or prohibits use of all or part of the property
- Emergency remedial action or an emergency prohibition order – where there is an imminent risk of serious harm
- Demolition order or clearance area – in the most serious cases
Financial penalties
The guide explains that councils can now:
- impose a civil penalty of up to £7,000 when first taking action on a Category 1 hazard in qualifying residential premises, where it would have been reasonably practicable for the landlord to remove it
- impose a civil penalty of up to £40,000 for failing to comply with an improvement notice, for offences committed on or after 1 May 2026 (£30,000 before that date)
How the HHSRS links to Awaab’s Law
Awaab’s Law uses the HHSRS list of hazards but works differently. The government’s guide notes that Awaab’s Law focuses on the circumstances of the actual tenant, while the HHSRS assesses risk for a notional vulnerable occupant, and that an HHSRS assessment is not required under Awaab’s Law.
| HHSRS | Awaab’s Law | |
|---|---|---|
| Who it applies to | All residential property in England; enforced mainly against landlords by councils | Social landlords in England (private sector date not confirmed) |
| Test | Scored risk to the most vulnerable age group | Significant or emergency risk to the actual household |
| Deadlines | Set in each council notice | Fixed in regulations (for example, investigate significant hazards within 10 working days) |
| Enforced by | Local councils | Tenants (contract claims, Housing Ombudsman) and the Regulator of Social Housing |
In practice, a damp and mould problem in a social home can engage both. For more, see what is Awaab’s Law, the Awaab’s Law timeline and our guide to Awaab’s Law for private landlords.
Other laws that apply to damp and mould
Landlords may also be liable under section 11 of the Landlord and Tenant Act 1985 (repairing obligations) and the Homes (Fitness for Human Habitation) Act 2018, which allows tenants to take action in court where serious hazards make a home unfit. Our housing disrepair survey and damp and mould expert witness services support landlords, tenants and solicitors in these cases.
How a damp and mould survey helps
An independent damp and mould survey gives you the evidence to understand the risk, fix the cause and respond to a council or tenant with confidence. Our Chartered Surveyors use moisture meters, thermal imaging, calcium carbide testing, salt analysis and airflow analysis, and record ambient temperature, relative humidity and dew point. You receive a written report with photographs, a risk rating and prioritised recommendations, and we can carry out a follow-up inspection to verify that repairs have worked.
Our survey is not a formal HHSRS assessment by a council, but it identifies the defects that drive HHSRS damp and mould scores so you can deal with them before they escalate.
Social landlords needing investigations within Awaab’s Law timescales can book an Awaab’s Law survey. Call 0151 374 0905 or email office@lansdownassociates.co.uk (Monday to Friday, 09:00 to 17:00).
Frequently asked questions
Is damp and mould a Category 1 hazard?
It can be. It depends on the HHSRS score, which reflects the likelihood and severity of harm. Serious, widespread damp and mould is more likely to score in the High band and be a Category 1 hazard.
What changed in the HHSRS in 2026?
From 23 June 2026 the number of hazards was cut from 29 to 21, scoring was simplified and three bands replaced the old A to J bands. Damp and mould remains a listed hazard.
Can a council fine a landlord for damp and mould?
Yes. Where a Category 1 hazard is found in qualifying residential premises, a council can impose a civil penalty of up to £7,000, and up to £40,000 for failing to comply with an improvement notice for offences from 1 May 2026.
Does the HHSRS apply to owner-occupied homes?
The HHSRS can be used to assess any home, whether rented or owned, but enforcement is mainly used in the rented sector.
