HHSRS damp & mould hazard scoring, explained.

Awaab's Law sets the deadlines; HHSRS (the Housing Health and Safety Rating System) is the methodology that decides how serious a damp or mould finding actually is. Understanding the scoring matters because it's what separates a Category 1 hazard — the ones with the hardest legal consequences — from a lower-risk finding that still needs recording and fixing, just without the same enforcement teeth.

Category 1 vs Category 2

Every HHSRS hazard gets a numerical score. Category 1 is a score of 1,000 or above — local councils have a mandatory duty to take enforcement action once a Category 1 hazard is identified in social housing. Category 2 is anything scoring below 1,000, split into moderate and low risk bands, where enforcement is discretionary rather than mandatory. Damp and mould growth is assessed as its own hazard profile within this system.

How the score is actually calculated

The hazard score combines two judgements, each made by the assessor on-site:

Likelihood of harm — the probability of a harmful outcome occurring in the next 12 months, assessed against the most vulnerable age group a home of that type could plausibly house, not necessarily the actual current occupant.
Severity of harm outcome — HHSRS classifies outcomes into four bands: Moderate, Serious, Severe and Extreme. GOV.UK guidance specifies harm must be "more serious than a minor scratch or bruise" to register at all.

Those two figures feed a published formula to produce the final score. It's a structured, published methodology — but the judgement calls (what's actually observed, how likely it is to recur, how severe the plausible outcome is) remain the assessor's, not a mechanical output software can generate on its own.

The 2026 reform, in one paragraph

From 23 June 2026, HHSRS itself was overhauled: 21 hazard profiles grouped into four themes, three plain bands (High = Category 1 at 1,000+, Medium, Low) replacing some of the older terminology, and new baseline indicators — for damp and mould specifically, a stated baseline is "no room has observable damp or mould growth or deterioration of internal finishes exceeding 5% of the wall or ceiling surface." HousingSurvey Pro's field app has the full 2026 assessment built in, so surveyors work against the current methodology rather than a superseded one.

Category 1 damp and mould vs the 24-hour emergency track

These are related but not identical. A Category 1 HHSRS score means mandatory enforcement applies — it doesn't automatically mean the hazard is an Awaab's Law emergency. The 24-hour track is reserved for hazards presenting an imminent and significant risk of harm; a Category 1 finding that isn't imminent typically still follows the standard 10-working-day investigate / 3-day written-summary / 5-day make-safe track. Getting this distinction right on site is exactly the kind of judgement call that needs to be recorded, not just made.

What to actually evidence

The specific observation — extent of mould/damp, affected surface percentage, room and location, not just "damp present".
The likelihood and harm-outcome judgement behind the score, in enough detail that someone reviewing the case later (a manager, an Ombudsman investigator, a solicitor) can see the reasoning, not just the number.
Dated, geo-stamped photos tied to the same property record as the score.
Which track the case is on (standard or emergency) and why.

That record then flows straight into your housing management system (HMS) or case-management system — see how integrations work — instead of being retyped from a paper checklist.

Sources: GOV.UK — Landlord and agent guide to HHSRS and Awaab's Law: guidance for social landlords. HHSRS assessment is a professional discipline in its own right — this page is an orientation, not assessor training, and the 2026 reform is recent enough that assessor-level operating guidance should be your primary reference for edge cases.

Capture HHSRS-scored evidence in the field — start free

Frequently asked questions

What HHSRS category is damp and mould?

Damp and mould growth is its own hazard profile under HHSRS. A hazard scores Category 1 (mandatory local-authority enforcement) at 1,000 points or above; below that it's Category 2 (moderate or low risk, discretionary enforcement). The score comes from the likelihood of harm over the next 12 months combined with the severity of the harm outcome, assessed against the most vulnerable plausible occupant age group, not just the actual tenant.

Is a Category 1 HHSRS damp and mould hazard the same as an Awaab's Law emergency?

Not automatically. Awaab's Law's 24-hour emergency track is for hazards presenting an imminent and significant risk of harm — a smaller, more urgent set than every Category 1 finding. A Category 1 damp and mould hazard that isn't imminent typically follows the standard 10/3/5-working-day track, not the 24-hour one.

Who decides the HHSRS score — the software or the surveyor?

The surveyor. HHSRS scoring is a professional judgement against a published methodology (likelihood and harm-outcome bands); software can structure the assessment and apply the published formula consistently, but the on-site judgement calls remain the surveyor's.

This page is general information, not legal advice, and is not a substitute for qualified HHSRS assessor training. Always confirm current methodology and requirements with your compliance team.