The short version
If you let a home in England, Scotland or Wales, you have a legal duty to assess the risk from legionella and to control it. For most homes HSE expects a simple assessment that you can do yourself. The law does not ask for a water test, a certificate, or a fresh assessment every year.
Who counts as a landlord
HSE’s definition: “A landlord is anyone who rents out a property they own under a lease or a licence that is shorter than 7 years.” It covers homes let by:
- local authorities
- housing associations
- private sector landlords
- housing co-operatives
- hostels
It also covers a room. HSE says the responsibilities apply “if you are a landlord and rent out your property (or even a room within your own home)”.
Where the duty comes from
There is no single legionella law. The duty comes from four places:
| Source | What it does |
|---|---|
| Health and Safety at Work etc. Act 1974 | Section 3(2) applies health and safety law to landlords, for the protection of their tenants. Under section 53 a landlord is treated as self-employed. |
| COSHH Regulations | The Control of Substances Hazardous to Health Regulations cover biological agents, legionella included. They set the pattern: identify and assess the risk, then control it. |
| Approved Code of Practice L8 | HSE’s code on controlling legionella in water systems. It explains what the Act and COSHH require of people who control premises, landlords included. |
| HSG274 Part 2 | HSE’s technical guidance for hot and cold water systems. Paragraphs 2.138 to 2.146 are about rented homes. |
What the duty is
HSG274 Part 2, paragraph 2.138, states it in one sentence:
Landlords who provide residential accommodation, as the person in control of the premises or responsible for the water systems in their premises, have a legal duty to ensure that the risk of exposure of tenants to legionella is properly assessed and controlled.
The same paragraph says the duty extends to “residents, guests, tenants and customers”. Paragraph 2.140 breaks the work into four parts. The law requires “simple, proportionate and practical actions”, including:
- Identifying and assessing sources of risk.
- Managing the risk.
- Preventing or controlling the risk.
- Periodically checking that any control measures are effective.
How much assessment is enough
HSE is direct about this. The duty to assess “does not require an in-depth, detailed assessment”. It goes on:
A simple assessment may show there are no real risks and these are being properly managed so no further action is needed. It is important to review the assessment in case anything changes in the system.
HSE gives an example of a typical low-risk home: a small building with a small domestic-type water system, where
- daily water usage is inevitable and sufficient to turn over the entire system
- cold water comes directly from a wholesome mains supply, with no stored water tanks
- hot water is fed from instantaneous heaters or low volume water heaters supplying outlets at 50 °C, and the only outlets are toilets and wash hand basins
Read that list again against a real house. Most rented homes have a shower, and many store hot water in a cylinder. Those homes are not automatically high risk, but they are not HSE’s low-risk example either. The assessment is how you find out which you have.
HSG274 Part 2 puts the general point this way: “All water systems require a risk assessment but not all systems require elaborate control measures.”
Stop and thinkA landlord says: “My flat has a combi boiler, so I don’t need a legionella risk assessment.” Is that right?Show the answer
No. The duty to assess applies to every let home. A combi boiler lowers the risk, because nothing is stored, and the assessment for that flat will be short. It still has to be done: the flat has outlets that may not be used, pipework that may have been altered, and a shower.
What the law does not require
A good deal of what landlords are told they need is not in the law. HSE says so plainly.
| Often claimed | What HSE says |
|---|---|
| “You need a legionella certificate.” | “Health and safety law does not require landlords to obtain or produce a ‘legionella test certificate’.” |
| “The water must be tested.” | Testing or sampling “is not usually required for domestic hot and cold water systems, and is only needed in very specific circumstances”. |
| “It must be redone every year.” | “The law does not prescribe that the risk assessment be reviewed on an annual or biennial basis.” It should be reviewed periodically in case anything changes. |
| “It must be done by a professional.” | “Most landlords can assess the risk themselves and do not need to be professionally trained or accredited.” |
| “You must keep a written record.” | Recording the findings is “only a statutory duty for employers where there are 5 or more employees”. HSE adds that “you may find it wise to keep a record of what has been done”. Lesson 8 explains why you should. |
One distinction to keep clear. Testing the water for bacteria is not the same as taking its temperature. HSE: “Testing for legionella should not be confused with temperature monitoring, which is a reliable method for confirming the water system is under control.” Temperatures are part of an assessment. Laboratory tests usually are not.
Who can carry out the assessment
HSE’s position, in full:
In most cases, the actions landlords need to take are simple and straightforward so compliance does not need to be burdensome or costly. Most landlords can assess the risk themselves and do not need to be professionally trained or accredited. However, if they do not feel competent, or inclined to do so, they can arrange for someone to do it on their behalf.
The word that matters is competent. HSE’s code of practice, L8, says the person who carries out the assessment “must be competent to do so”, and that they should know:
- the potential sources of legionella bacteria and the risks they present
- the measures to adopt, including the precautions that protect the people concerned, and why they matter
- the measures that keep the controls effective, and why they matter
The same code says training is not the only factor. Instruction, experience and knowledge count as well. This course gives you the knowledge. It is not a qualification, and reading it does not by itself make anyone competent: that comes from understanding the material and applying it carefully to a real property.
Someone already visiting the property can do it. HSE names “mandatory visits such as gas safety checks or routine maintenance visits” as times when the water system can be inspected. More on this in who can carry out a legionella risk assessment.
Letting agents
HSG274 Part 2, paragraph 2.139:
Where a managing (or letting) agent is used, the management contract should clearly specify who has responsibility for maintenance and safety checks, including managing the risk from legionella. Where there is no contract or agreement in place or it does not specify who has responsibility, the duty is placed on whoever has control of the premises and the water system in it, and in most cases, this will be the landlord themselves.
Two things follow. If you are a landlord, read your management contract and see what it says about legionella. If you are an agent, make sure yours says something. There is more in legionella risk assessments and letting agents.
Stop and thinkAn agent manages a house on a contract that does not mention legionella at all. Who holds the duty?Show the answer
Where the contract does not say, HSG274 Part 2 places the duty on whoever has control of the premises and the water system, and says that in most cases this will be the landlord. The agent should still raise it, and the contract should be put right.
Flats and shared buildings
A flat often takes its water from plant the landlord of the flat does not control: a shared tank on the roof, a booster pump, a communal hot water system. HSG274 Part 2 says that in a building with several parties, the duty follows the agreement between them. A common arrangement is that “the owner takes responsibility for the common parts while the leaseholders take responsibility for the parts they occupy”. Where no agreement says who is responsible, “the duty is placed on whoever has control of the premises, or part of the premises”.
In practice, for a let flat:
- Assess the water system inside the flat. That part is yours.
- Ask the freeholder or managing agent how water reaches the flat, whether any of it is stored communally, and whether the building has its own legionella risk assessment.
- Keep their answer with your assessment.
Large numbers of homes
Councils and housing associations may have thousands of homes. HSG274 Part 2, paragraph 2.146, accepts that assessing every one at once may be impractical. It says “a representative proportion of the premises for which they have responsibility should initially be assessed, on the basis of similar design, size, age and water supply, with the entire estate eventually assessed on a rolling programme of work”.
Will anyone check?
HSE says its inspectors and local authority inspectors “do not proactively inspect domestic premises or ask for evidence that landlords have carried out a risk assessment”.
The duty exists whether or not anyone checks. If a tenant did become ill from the water system in their home, HSE says the landlord would have to show that they had met their legal duty. An assessment that was done properly, written down and acted on is how that is shown.
England, Scotland and Wales
The Health and Safety at Work etc. Act applies across Great Britain, so the duty in this lesson is the same in England, Scotland and Wales. Some kinds of letting carry extra rules of their own. Two examples: short-term lets in Scotland and rented homes in Wales.