Legionella risk assessment template for HMOs
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Key points
- An HMO assessment follows the same ACOP L8 framework as a single let, but the template has to have room for shared plant, more occupants, and void periods.
- HMOs are the standard worked example because one converted house contains nearly every feature an assessor has to think about: a communal tank, shared hot-water plant, showers, and a flat standing empty.
- A simple single-let template is enough where each flat has its own combi boiler and there is no shared water system; shared storage or a communal cylinder needs the fuller assessment.
- The void flat is usually the highest-risk part of an HMO: its outlets go onto weekly flushing until it is re-let, and every flush is logged.
- A template records your checks; it never certifies the building. Keep the records for at least five years.
An HMO legionella risk assessment uses the same five-step ACOP L8 framework as any rented property, but the template has to cover more ground: shared tanks and hot-water plant, more occupants using the system, and flats that stand empty between tenancies. A one-page single-let template is enough for a simple flat with a combi boiler; a shared-system HMO needs the fuller version.
That is why the HMO is the worked example assessors reach for first. A single converted house contains, under one roof, almost every feature a legionella assessment has to consider: stored cold water, stored hot water, showers in every flat, pipework altered during conversion, and at least one outlet that is not being used. If a template can handle an HMO, it can handle anything simpler. If it can only handle a simple single let, it will run out of room on the first page of an HMO.
What the assessment looks like for a six-flat conversion
Take the standard conversion: a Victorian terrace split into six self-contained flats. The incoming main feeds a communal cold-water storage tank in the loft. The tank feeds a single gas-fired calorifier in a ground-floor plant cupboard, which stores hot water and distributes to all six flats. Each flat has a mixer shower over a bath. Flat 4 has been empty for two months. Nothing exotic — and yet the assessment for this building has to record all of the following.
| System component | What the assessment notes | Control and typical frequency |
|---|---|---|
| Communal cold-water tank (loft) | Condition, close-fitting lid, insulation, stored water temperature | Inspect periodically; keep stored cold below 20°C as far as practicable |
| Gas-fired calorifier (plant cupboard) | Stored hot water temperature | Held at 60°C; check the stored temperature monthly |
| Hot water at sentinel outlets (nearest and furthest from the calorifier) | Time to reach temperature | Check monthly; at least 50°C within one minute of running |
| Cold water at sentinel outlets | Time to drop below 20°C | Check monthly; below 20°C within two minutes of running |
| Showers, one per flat (six in total) | Scale and condition of heads and hoses | Descale and disinfect quarterly; written guidance given to tenants |
| Flat 4 (currently void) | Every outlet unused for the duration of the void | Flush weekly to temperature and log it until re-let; flush the whole flat through before new tenants move in |
| Capped pipe run to the old communal bathroom, removed during conversion | Redundant length holding stagnant water (a dead leg) | Cut back and remove where practicable; until then, flush weekly and record |
| Tenant turnover in any flat | Change of occupancy, possible change in tenant vulnerability | Flush before reoccupation; review the assessment |
Work through that table and the shape of the HMO template becomes clear. It needs a plant schedule (the tank, the calorifier, the pipe runs), a list of sentinel outlets with target temperatures, a named person who carries out each check, and a log sheet for flushing and temperature readings. Our free risk assessment builder walks through these components one by one, and the temperature checker tells you whether the readings you take are in range. The results belong in a log book, kept for at least five years.
Free legionella risk assessment template
A structured Word document following the five-step approach in ACOP L8. Covers risk identification, written scheme, monitoring, and records. If it isn't written down, you can't evidence it.
Follows ACoP L8 and HSG274 Part 2. Free. No spam.
When a single-let template is enough, and when an HMO needs more
The duty itself is identical for every let; what changes is how much there is to write down. Our guide to legionella for landlords covers the single-let position in full. The decision point is the water system, not the paperwork label:
| What you have | What is proportionate |
|---|---|
| Single flat or house, combi boiler, mains-fed, no stored water, one household | The free single-let template, completed and kept. A page or two is usually enough. |
| HMO where every flat has its own combi boiler and there is no shared water system | The single-let template applied per flat, plus a short note covering any communal pipework. Still a simple system. |
| HMO with a shared cold-water tank, a communal calorifier or cylinder, or complex conversion pipework | The fuller assessment: plant schedule, sentinel outlets, named responsible person, written scheme of control, and a flushing and temperature log. |
| HMO with vulnerable occupants, a history of temperature problems, or plant you cannot confidently assess yourself | The fuller assessment, and for many landlords a competent external assessor to carry it out or review it. |
Two features push a property out of the simple category: shared stored water, because it creates a communal point where the whole building’s supply can warm up or stagnate; and void periods, because an empty flat is a branch of the system with no turnover at all. A conversion usually has both, plus the legacy pipework that conversions leave behind. Our pages on dead legs and flushing little-used outlets cover those two controls in detail.
Who does what: freeholder, landlord and agent
In a converted block, responsibility for the communal water system — the loft tank, the shared calorifier, the risers — usually sits with the freeholder or their managing agent, while each landlord remains responsible for the water system inside their own let. If you own the whole converted building, you hold both. Where a managing agent runs the block, delegate the tasks in writing and confirm the flushing and temperature checks are actually being done; the overarching duty cannot be signed away. The split is explained in who is responsible for legionella in rented property, and the document that allocates the tasks is the written scheme of control.
The Pro Pack — £29
The Pro Pack bundles the editable risk assessment and written scheme of control documents — the structure you lay out for shared plant, sentinel outlets and void-flat flushing — with a formula-driven log book for the temperature and flushing records, and a complete worked example for a single-let flat showing what a filled-in assessment reads like. It is an indicative starting point: it structures what you check and records when you checked it. It never certifies a building as safe — you still walk the property, take the temperatures, and keep the log. The free single-let template remains available if that is all your property needs.
What the template does and does not do
A completed template is evidence that you assessed the system, set controls, and carried them out. It is not a certificate, and there is no such thing as a legionella certificate for landlords in England and Wales, whatever it is called by whoever is selling one. What an inspector, a licensing officer, or an insurer will look for is the record: the assessment itself, the written scheme, and the log showing weekly flushes of the void flat and monthly temperatures at the sentinel outlets.
In an HMO the risk concentrates where the water stands still: the shared tank nobody opens, and the void flat nobody uses. The assessment that matters is the one that names those outlets and logs the flush every week.
Review the assessment whenever the building changes — a new cylinder, a removed tank, a long void, or a shift towards more vulnerable tenants — and about every two years in any case. If you are not yet sure whether your property needs an assessment at all, our guide on whether you need a legionella risk assessment works through the question, and ACOP L8 explained sets out the legal framework the template follows.
Free legionella risk assessment template
A structured Word document following the five-step approach in ACOP L8. Covers risk identification, written scheme, monitoring, and records. If it isn't written down, you can't evidence it.
Follows ACoP L8 and HSG274 Part 2. Free. No spam.
Frequently asked questions
Do HMOs need a legionella risk assessment?
Yes. The landlord of a house in multiple occupation holds the same duty under the Health and Safety at Work etc. Act 1974 and COSHH as any other landlord: assess the risk from the water system, control it, and keep written records. An HMO does not change the duty, but it changes what is proportionate, because shared tanks or plant, more occupants, and flats standing empty between tenancies all raise the risk that has to be assessed. Some councils also ask to see a written water-risk assessment as part of HMO licensing, so having it recorded is useful beyond the health and safety duty itself.
Can a landlord do their own legionella risk assessment on an HMO?
Yes, provided they are competent: they understand the water system in their own building, can identify tanks, cylinders, little-used outlets and dead legs, and can take and record temperatures. Where the HMO has shared stored water, a communal calorifier, complex pipework, or particularly vulnerable occupants, many landlords bring in a competent external assessor instead. Whoever carries it out, the output is the same: a written assessment, a written scheme of control, and a record of the checks that follow.
Is a legionella test certificate required for an HMO?
No. There is no legal legionella test certificate for landlords in England and Wales, in an HMO or anywhere else, and routine water sampling is not normally required for domestic hot and cold water systems. The legal duty is the risk assessment and the records that follow it. Sampling has a place where controls are not working, where occupants are especially vulnerable, or where the assessment itself recommends it, but a lab test is not a substitute for assessing and controlling the system.
How often should an HMO legionella risk assessment be reviewed?
There is no fixed legal interval. The usual practice is to review about every two years, and sooner on trigger events: plumbing alterations such as a new cylinder or removed tank, a change in the tenant mix towards more vulnerable occupants, a long void period in any flat, or any sign the controls are failing, such as outlets that will not reach temperature. In an HMO, turnover itself is a review trigger, because each void changes how much of the system is stagnating.
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