HHSRS: the 21 hazards explained

Updated 30 October 2026 · reflects SI 2026/571, in force 23 June 2026

The Housing Health and Safety Rating System is the method English councils use to decide whether a home is safe enough to live in. It was introduced by the Housing Act 2004 and replaced the old fitness standard with something quite different: instead of asking “does this property meet a specification?”, the HHSRS asks “how likely is it that something in this property will harm the person most vulnerable to it, and how badly?”

That shift matters to landlords in a way that is easy to miss. There is no checklist you can satisfy to be HHSRS-compliant, because the system has no pass mark expressed in materials or dimensions. It is a risk assessment of 21 prescribed hazards, carried out by an officer, on your particular property, against a defined vulnerable group. The way to stay on the right side of it is to understand the 21 categories and know which ones your stock is exposed to.

This guide covers the whole system as it stands after the June 2026 reform: what changed and which old hazards were folded into which new ones, how a hazard is scored under the new bands, what separates a Category 1 from a Category 2 hazard, what enforcement follows, and then every one of the 21 hazards with what actually triggers it in a rented home.

What changed on 23 June 2026

Regulation 8 of SI 2026/571 amended Schedule 1 to the 2005 Regulations, which is the list of prescribed hazards. It inserted five new paragraphs — 4A, 14A, 18A, 23A and 25A — and omitted thirteen: paragraphs 5, 6, 9, 10, 15, 16, 17, 19, 20, 24, 26, 27 and 28. Twenty-nine hazards became twenty-one. Nothing was deleted from the system in the sense of ceasing to be a hazard; the narrower descriptions were merged into broader ones.

Three other changes in the same instrument are worth knowing:

• The fire hazard got wider. The prescribed fire hazard in regulation 4 of the 2005 Regulations now expressly covers the fumes associated with uncontrolled fire, explosion, and the collapse of a building as a result of fire or an explosion.
• Structural collapse is no longer limited to the let unit. Paragraph 29 was amended so that it refers to the collapse of “a building” rather than “the dwelling or HMO”.
• The classes of harm were renamed. Classes I to IV became extreme, severe, serious and moderate. The classes themselves, and their place in the scoring formula, were not otherwise changed.

The reform came with new statutory Operating Guidance and Enforcement Guidance, both published on 23 June 2026, a set of illustrated case studies in July 2026, and refreshed landlord, agent and tenant guides in September 2026. GOV.UK describes the exercise as “reducing the number of hazards from 29 to 21”.

What the HHSRS is — and what it is not

The HHSRS applies to residential premises of every tenure, not just rented ones, and it is used by local housing authorities exercising their functions under Part 1 of the Housing Act 2004. Three things it is not:

• Not a certificate. There is no “HHSRS certificate” you can buy, and no document that proves compliance. What exists is an assessment, and the record of it.
• Not a standard you can build to. It does not specify minimum dimensions or products. Building Regulations, HMO licence conditions and amenity standards do that; the HHSRS evaluates risk in the property as it is.
• Not about the current occupant. With one exception, the assessment is made against the age group most vulnerable to that particular hazard, whether or not anyone in that group lives there. A house let to four twenty-five-year-olds is still assessed for falls on stairs against the risk to an older person. The exception, per GOV.UK’s 2026 landlord and agent guide, is crowding and space, which is assessed against the household that is actually there.

That vulnerable-group point is the one landlords most often argue with and it is the one least worth arguing. “No children live here” is not an answer to a damp and mould hazard scored against children.

How a hazard is scored under the 2026 rules

An officer assessing a hazard asks two questions and combines the answers:

1. Likelihood. Over the next twelve months, what is the chance that an occupant in the vulnerable group suffers harm from this hazard? The Regulations still express this as a ratio — one in 100, one in 1,000 and so on — sorted into a graduated table of ranges, each mapped to a single representative scale point. The 2026 amendment replaced that table with a tidier set of round numbers, running from 5,000 at the least likely end down to 1 at the most likely. It did not reduce the number of ranges: there were sixteen before and there are sixteen now.
2. Spread of harm outcomes. If harm does occur, how is it likely to be distributed between the four classes of severity? Each class gets a percentage drawn from a second table of ranges, likewise re-cut into rounder figures in 2026.

Worth flagging, because it is widely repeated: several secondary summaries state that the sixteen likelihood categories were reduced to four. That is not what SI 2026/571 did to the Regulations — Table 1 still has sixteen ranges. What GOV.UK’s landlord and agent guide describes is the assessor-facing presentation, where likelihood is grouped into a handful of broad descriptors running from very likely to very unlikely. The underlying arithmetic is unchanged in structure. Treat the “four likelihoods” line as a description of the guidance, not of the scoring table.

The weightings in the scoring formula were not amended in 2026; only the class names changed. The likelihood and the weighted spread are combined into a single numerical hazard score, and that score now falls into one of three bands rather than ten letters. The scoring is still done hazard by hazard: a property does not get one overall HHSRS score, it gets a score for each hazard assessed.

Scores are not capped at 5,000: a seriously defective property can score in the tens of thousands. GOV.UK’s own worked example of an excess cold hazard in a home with no properly installed heating system scores 31,145.

Category 1 versus Category 2 — what did and did not change

This is the part most of the commentary gets muddled, so to be clear: the enforcement duties did not change in 2026, and neither did the threshold. The dividing line still sits at a hazard score of 1,000. All regulation 7 of SI 2026/571 did was swap the words “band A, B or C” for “the High band”, and “any other band” for “the Medium or Low bands”. A hazard that would have been Category 1 on 22 June 2026 is Category 1 on 23 June 2026.

• Category 1 hazard (High band, 1,000 or more). The council has a duty to take the most appropriate enforcement action. It is not optional, and it is not negotiable away — although which action it takes, and whether it is suspended, involves judgement.
• Category 2 hazard (Medium or Low band, under 1,000). The council has a discretionary power to take action but no duty. Many councils publish policies on when they will act on Category 2 hazards; the new Medium/Low split gives those policies a cleaner line to draw than the old bands D to J did.

Note that Category 2 has not been formally subdivided in law — it is a single category covering two bands. But because Medium and Low are now named, in practice a Medium-band Category 2 hazard reads very differently in a report from a Low-band one, and GOV.UK’s tenant guide does describe Category 2 hazards as moderate or low risk.

A single Category 1 hazard is enough to trigger the duty. It does not matter that the other twenty hazards were all clear.

What enforcement follows

Part 1 of the Housing Act 2004 gives councils a range of tools, and the 2026 amendment did not touch them. These are the ones you are likely to meet:

Alongside those, councils can charge for the costs of taking enforcement action, impose a financial penalty of up to £30,000 as an alternative to prosecution for certain housing offences, and support tenant applications for rent repayment orders. Formal notices carry a right of appeal to the First-tier Tribunal (Property Chamber) within the period stated on the notice, so read the notice properly and diary the deadline the day it arrives.

One further consequence worth noting: a hazard that an officer would score in the High band is also likely to engage the Homes (Fitness for Human Habitation) Act 2018, which lets a tenant sue directly for breach of an implied term that the property is fit for human habitation, seeking both works and damages. Enforcement by the council is not the only route any more.

The 21 hazards

Below is the list as it now stands. The numbering follows the order used in the 2026 GOV.UK guidance, which leads with the accident hazards; the paragraph number in brackets is the statutory reference in Schedule 1 to the 2005 Regulations as amended, which runs in a different order because the five new paragraphs were inserted alongside the surviving ones. Either reference will find the right hazard. The grouping by class of need has no legal significance in itself, but it helps when you are working out which hazards apply to a particular building.

Protection against accidents (hazards 1–8)

1. Falls on the level (Schedule 1, para 18A). New in 2026, and a merger of two of the old hazards. It covers falls associated with a bath, shower or other washing facility, falls on any level surface — floors, yards, paths, thresholds — and falls where the change in level is under 300 mm. Worn or rucked floor coverings, uneven paving, raised thresholds, poorly lit routes, a high bath rim with no grab rail, and slippery shower bases all sit here. Mundane, extremely common, and responsible for a large share of housing injuries.
2. Falls on stairs, steps and ramps (Schedule 1, para 21). Falls on internal or external stairs, steps and ramps where the change in level is 300 mm or more. Assessed on consistency of riser and going, pitch, handrails on both sides where needed, balustrade gaps, winders, nosings, lighting and headroom. Poorly built loft conversions and space-saver stairs are repeat offenders.
3. Falls between levels (Schedule 1, para 22). Falls from one level to another where the difference is 300 mm or more — out of windows, from balconies, landings, flat roofs, over low balustrades or into basement areas. The vulnerable group is young children. Low-silled upper-floor windows without restrictors, and balustrades with climbable or wide-spaced infill, are the classic findings.
4. Fire and explosions (Schedule 1, para 23A). Also new in 2026, merging the old fire and explosions hazards into one. It covers exposure to uncontrolled fire and the smoke and fumes that come with it, and injury from an explosion — the blast, the debris, and the collapse of a building caused by fire or explosion. Assessed on sources of ignition, the spread of fire and smoke, detection and warning, and the means of escape. In shared housing this is the single highest-consequence hazard and is read alongside fire safety law and the LACORS fire safety guidance for existing housing. Bottled gas stored inside a dwelling or on an escape route is a serious finding in its own right.
5. Flames, hot surfaces and materials (Schedule 1, para 25). Burns from contact with controlled flames or hot surfaces, and scalds from hot liquids and vapours — including hot water from a tap or shower. The vulnerable group is young children. Unguarded heaters, exposed hot pipework, hob position relative to circulation space, and uncontrolled hot water outlet temperatures are all assessed here.
6. Collisions, entrapment and ergonomics (Schedule 1, para 25A). Another 2026 merger. It covers trapping body parts in doors, windows, hatches, gates and other architectural features, striking surfaces such as low beams, low door heads, unmarked full-height glazing and badly placed projections, and the position, location and operability of amenities, fittings and equipment — baths, WCs, sinks, cupboards, windows, doors, stairs and stores placed where they cannot be used without strain or contortion. The ergonomics limb is what used to be “position and operability of amenities”.
7. Structural collapse and falling elements (Schedule 1, para 29). Injury from the collapse of all or part of a building, and from falling elements — ceilings, chimneys, parapets, balconies, external render, roof coverings, slipped slates, loose copings, failed lintels, outbuildings and boundary walls. The 2026 amendment widened this from “the dwelling or HMO” to “a building”, so a dangerous structure outside the let unit itself is now plainly in scope. Garden and boundary structures matter.
8. Electrical hazards (Schedule 1, para 23). Shock and burns from exposure to electricity, including from lightning. Assessed on the condition and adequacy of the fixed installation: protective devices, earthing and bonding, RCD protection, the number and position of socket outlets, and the condition of accessories. This is the hazard the five-yearly EICR exists to control — see our certificate deadlines guide.

Physiological requirements (hazards 9–15)

9. Excess cold (Schedule 1, para 2). Threats to health from sub-optimal indoor temperatures; the vulnerable group is older occupants. Assessed across the whole dwelling, looking at the heating system, its controllability and running cost, insulation, glazing and draughts. Excess cold and damp very often appear together, and a property failing on energy efficiency will frequently fail here too.
10. Radiation (Schedule 1, para 8). Threats from radon gas and its decay products, mainly in radon-affected areas and mainly accumulating in ground floors, basements and poorly ventilated spaces. UK Health Security Agency maps identify affected areas; where a property sits in one, testing is inexpensive and remediation (sump, membrane, positive ventilation) is well established.
11. Damp and mould growth (Schedule 1, para 1). Threats to health from house dust mites, mould and fungal growth caused by damp, high humidity and condensation. The vulnerable group is children. This is the most commonly assessed hazard in the private rented sector and the one behind Awaab’s Law. Causes split into penetrating damp (roof, gutters, pointing, failed flashing), rising damp, plumbing leaks, and — most often — condensation driven by inadequate heating, insulation or extract ventilation.
12. Lead (Schedule 1, para 7). Threats from the ingestion of lead, principally from old lead water pipes and from deteriorating pre-1970s lead-based paint that children can chew or inhale as dust during poorly controlled stripping. Check the incoming main in older properties, and treat any flaking paint in a pre-1970s property as suspect until proven otherwise.
13. Indoor air pollutants (Schedule 1, para 4A). The biggest of the 2026 mergers: four former hazards in one. It covers chemicals used to treat timber and mould growth (the old biocides hazard), carbon monoxide, nitrogen dioxide, sulphur dioxide and smoke (the old fuel combustion products hazard), uncombusted fuel gas, and volatile organic compounds. In practice: badly installed, badly maintained or badly ventilated combustion appliances, blocked or shared flues, solid-fuel appliances, gas leaks, and the off-gassing of paints, adhesives, solvents and new furnishings after a refurbishment. This is the hazard behind the annual gas safety check and the carbon monoxide alarm requirement. Potentially fatal, cheap to control, expensive to ignore. Some GOV.UK guidance refers to it as “chemical and combustion related air pollutants”; the statutory name in Schedule 1 is indoor air pollutants.
14. Excess heat (Schedule 1, para 3). Threats from excessively high indoor temperatures. Driven by solar gain through large unshaded glazing, poor cross-ventilation, top-floor flats under uninsulated roofs, and increasingly by over-sealed, over-glazed conversions that cannot be ventilated at night.
15. Asbestos and manufactured mineral fibres (Schedule 1, para 4). The presence of respirable asbestos fibres and manufactured mineral fibres in the air. Undisturbed asbestos-containing material in good condition is generally not the hazard — damaged, drilled, sanded or disturbed material is. Artex coatings, textured ceilings, insulating board, old boiler flues, water tanks, garage and outbuilding roofs and floor tiles in pre-2000 properties are the usual suspects. Never let a contractor work on them blind.

Protection against infection (hazards 16–17)

16. Domestic hygiene (Schedule 1, para 14A). A 2026 merger of three former hazards — domestic hygiene, pests and refuse; food safety; and personal hygiene, sanitation and drainage. The single paragraph now covers facilities for the storage, preparation and cooking of food; design or layout that makes the dwelling hard to keep clean; access and harbourage for pests; storage and disposal of household waste; personal washing facilities; and sanitation and drainage. In HMOs this is where undersized bin provision, an unventilated bathroom, too few WCs or wash-hand basins for the household count, a shared kitchen with no cleanable worktop or insufficient refrigeration, a defective trap or a leaking soil pipe all now score — under one heading rather than three.
17. Water supply for domestic purposes (Schedule 1, para 18). Threats from contaminated water and from an inadequate supply — quality, quantity and continuity. Legionella risk from stored or stagnant hot and cold water sits here, as do cross-connections, dead legs, and tanks without proper covers.

Psychological requirements (hazards 18–21)

18. Crowding and space (Schedule 1, para 11). Threats to psychological wellbeing from a lack of space for living, sleeping and normal household life. Assessed on the usable space in relation to the household, not simply on headcount — and, unusually, GOV.UK guidance notes this is the one hazard assessed against the current household rather than a vulnerable age group. In HMOs it interacts directly with the mandatory licence conditions on sleeping room sizes — 6.51 m² for one person over 10 and 10.22 m² for two — which we cover in the HMO inspection checklist.
19. Entry by intruders (Schedule 1, para 12). Difficulties in keeping the dwelling secure against unauthorised entry. Assessed on the physical security of doors, locks, glazing and windows, the visibility of entrances, and external lighting. In shared housing it extends to the security of individual letting room doors and to who holds keys.
20. Noise (Schedule 1, para 14). Threats to wellbeing from exposure to noise inside the dwelling or within its curtilage — including noise transmitted between units in a poor conversion, noisy plant, and inadequate sound insulation between a flat and a commercial premises below. A frequent finding in flats converted without any acoustic upgrade to the separating floor.
21. Lighting (Schedule 1, para 13). Threats to physical and mental health from inadequate natural or artificial light, including glare and the psychological effect of obstructed views out. Small or obstructed windows, rooms converted from internal spaces, basement rooms and poorly lit stairs and common parts are the usual findings.

Which hazards actually get landlords served?

In practice a small number of the 21 account for most private-sector enforcement:

• Damp and mould growth — by a wide margin the most common, and now the subject of statutory repair timescales under Awaab’s Law.
• Excess cold — often found in the same properties, and increasingly visible because the EPC tells the council where to look.
• Fire and explosions — particularly in HMOs and converted flats, where it overlaps with fire safety law and licence conditions.
• Falls on stairs, steps and ramps and falls between levels — conversions and loft rooms.
• Electrical hazards and indoor air pollutants — usually where an EICR or gas safety record has lapsed.
• Domestic hygiene — in shared housing where amenity provision has not kept up with occupancy. This one now bundles kitchen facilities, bathrooms, drainage, pests and waste, so a single finding can be broader than it would have been before June 2026.

If you only have the appetite to audit a handful of hazards across a portfolio, audit those. Most of them are substantially controlled by keeping certificates in date and ventilation working.

How to self-assess sensibly

You cannot replicate a formal HHSRS assessment without the Operating Guidance and training — and you do not need to. What a landlord or agent needs is a repeatable inspection that captures the same evidence an officer would look for, so that problems are found and fixed before they are scored. A workable approach:

1. Go hazard by hazard, room by room. Walk the property with the 21 categories in front of you and note which are plausibly in play. Most properties engage fewer than ten.
2. Re-check your own templates. If your inspection form, spreadsheet or software still lists 29 hazards, it is out of date — and worse, it will not prompt for the full breadth of the merged categories. A form that still asks about “food safety” alone will miss the drainage and pest limbs of the new domestic hygiene hazard.
3. Record the evidence, not the conclusion. A photograph of a mouldy reveal with a date on it is worth more than a tick in a box labelled “damp: satisfactory”.
4. Think in terms of the vulnerable group. Ask who would be hurt worst, not who currently lives there — except on crowding and space.
5. Deal with cause, not symptom. Painting over mould, or treating it without fixing the ventilation or heating that caused it, is the recurring failure in damp cases and it is what turns a repair issue into an enforcement issue.
6. Close the loop. Every finding needs an action, an owner, a date and evidence of completion. Half of the enforcement risk in housing is not the defect; it is the inability to show what you did about it and when.
7. Keep tenant reports in the same file. Dates on which a tenant reported a problem are now legally significant, and under Awaab’s Law in social housing they start a clock.

Where the HHSRS is heading

The June 2026 reform answered a long-standing criticism — that the system was too complex for landlords and tenants to understand — by simplifying the hazard list and the bands rather than by changing the underlying risk model. More is coming. Government has legislated to extend a Decent Homes Standard to the private rented sector, with the detail to follow in regulations, and the consultation on extending Awaab’s Law to private tenancies proposes coverage of nearly all HHSRS hazards. Separately, the Renters’ Rights Act 2025 received Royal Assent on 27 October 2025, the new tenancy system commenced on 1 May 2026, section 21 “no-fault” evictions have been abolished, and a private rented sector database begins rolling out from late 2026.

The practical consequence of all of that is the same: property condition becomes more visible, more documented, and harder to deal with reactively. The landlords who find the transition easy are the ones who already inspect on a schedule and keep the evidence.

Primary sources

• The Housing Health and Safety Rating System (England) (Amendment) Regulations 2026 (SI 2026/571) — in force 23 June 2026
• HHSRS (England) Regulations 2005, Schedule 1 — the prescribed hazards, as amended (consolidated)
• Housing Act 2004, Part 1 — housing conditions
• GOV.UK — HHSRS guidance collection, including the 2026 Operating Guidance and Enforcement Guidance
• GOV.UK — HHSRS landlord and agent guide
• Homes (Fitness for Human Habitation) Act 2018

Related guides

• HMO Inspection Checklist for UK Landlords
• Gas, EICR and EPC: Landlord Certificate Deadlines
• Awaab's Law: What Landlords Need to Know

This guide is general information for UK landlords, agents and property managers, not legal advice. Standards are enforced locally and the law changes — check GOV.UK or your local authority’s published standards for your own situation, and take professional advice where it matters.