Housing is one of the wider determinants that shape health outcomes across London long before anyone sets foot in a GP surgery or A&E department, and few housing conditions illustrate that more directly than damp and mould. It is not simply an aesthetic nuisance: under national regulation it is formally classified as a health hazard, and since 2023 a new legal duty known as Awaab’s Law has begun setting hard deadlines for how quickly social landlords must respond. Understanding how that hazard is assessed, and what the new timelines actually require, is essential to understanding why housing quality remains one of the clearest levers on the wider health gap between London’s boroughs.
Why Damp and Mould Counts as a Housing Hazard, Not Just an Inconvenience
In England, the condition of a rented home is not judged informally. Local council environmental health officers assess it against the Housing Health and Safety Rating System (HHSRS), a risk-assessment framework introduced under the Housing Act 2004 that applies to all rented properties. HHSRS groups potential hazards into broad categories covering the body’s basic physiological needs, psychological wellbeing, infection risk, and accident risk. Damp and mould growth sits explicitly within the physiological group, alongside hazards such as excess cold, carbon monoxide and asbestos, because prolonged exposure to fungal growth and the house dust mites it supports is linked to allergies, asthma and other respiratory and wellbeing problems. Officers who identify a hazard classify it as either Category 1, a serious threat that local authorities are obliged to act on, or the less severe Category 2.
How the Assessment Works in Practice
An HHSRS inspection does not simply note that mould is present. It weighs the likelihood of harm against how severe that harm could be, producing a score that determines whether a hazard is serious enough to trigger enforcement action. This is why two homes with visible mould patches can be treated very differently: the extent of the growth, the ventilation and heating in the property, and the vulnerability of the people living there (young children and older residents are more susceptible to the respiratory effects) all feed into the rating. It is also worth noting that the underlying hazard list itself has recently been simplified, reducing the historic set of 29 distinct hazard categories to a smaller, more streamlined 21 as councils update how they apply the framework.
What Awaab’s Law Changes for Social Landlords
The Housing Act framework tells councils how to assess a hazard. Awaab’s Law, introduced through the Social Housing (Regulation) Act 2023 and named after Awaab Ishak, a two-year-old who died following prolonged exposure to mould in his family’s social housing, goes further by fixing how quickly a landlord must actually respond once a hazard is reported. Its duties covering damp and mould began to take effect from October 2025 and are being phased in, but the core timetable is now specific and enforceable rather than a matter of landlord discretion.
| Stage | Timeframe under Awaab’s Law |
|---|---|
| Emergency hazard (immediate risk to health or safety) | Investigated and made safe within 24 hours |
| Investigation of a reported damp or mould issue | Must begin within 10 working days of the report |
| Written summary of findings to the resident | Within 3 working days of the investigation finishing |
| Required safety work | Completed within 5 working days of the investigation concluding |
| Preventative works to stop recurrence | Started within 5 working days; full complex repairs within 12 weeks |
| Property cannot be made safe in time | Landlord must arrange and pay for alternative accommodation |
Taken together, these duties compress what was often an open-ended repairs process into a sequence of fixed, working-day deadlines, with a legal backstop, in the form of covered alternative accommodation, if a landlord cannot meet them.
Why This Sits at the Centre of London’s Wider Health Gap
Housing quality was identified as one of the wider determinants of health when London’s health system was reviewed in the last decade, alongside employment and environmental conditions, precisely because these factors operate outside clinical settings yet strongly shape who ends up needing NHS care. Damp and mould exposure is a textbook example: a housing-sector hazard whose consequences, worsened asthma, respiratory infections, and disrupted sleep and wellbeing, surface as demand on GPs, urgent care and hospital respiratory services. A regulatory tool that forces faster repairs is, in that sense, a public health intervention as much as a housing one, even though it sits in tenancy law rather than clinical guidance.
What Residents and Landlords Should Actually Do
The practical sequence under HHSRS and Awaab’s Law is straightforward, even if navigating it can feel anything but. A resident who reports damp or mould should expect an acknowledgement and, for social housing, a formal investigation opening within the ten-working-day window described above. If the property is later found to have a Category 1 hazard, the council has a duty to ensure action is taken, not merely to record the finding. Landlords, in turn, need a process that can actually meet those clocks: a route for residents to report issues, a way to log when the ten-day and five-day windows start, and a decision-maker who can authorise repairs or emergency works without delay. Where a fix genuinely cannot be completed quickly, the law does not allow a household to simply wait it out; the alternative-accommodation duty exists precisely so a resident is not left living with an unresolved health hazard while paperwork moves.
For residents, the practical takeaway is that damp and mould is no longer something a landlord can treat as low priority admin. It has a defined hazard classification, an assessment framework, and, for social tenants specifically, an enforceable clock. For anyone tracking why housing keeps recurring in discussions of London’s health inequalities, Awaab’s Law is the clearest recent example of policy trying to close the gap between where health outcomes are decided and where healthcare is delivered.