Compliance Guide
Legionella Risk Assessment for Landlords — Requirements, Costs & Water Safety
Landlord guide to Legionella risk assessments: HSE requirements, costs (£75–£200), what the assessment covers, and how to prevent Legionella in rental properties.
Legionella Quick Reference
Legal basis
Health and Safety at Work etc. Act 1974, s.3 (duty to non-employees). Control of Substances Hazardous to Health Regulations 2002 (COSHH), Regulation 6. HSE Approved Code of Practice L8: Legionnaires' disease — The control of legionella bacteria in water systems. HSG274 Part 2: The control of legionella bacteria in hot and cold water systems.
Renewal cycle
Every 2 years
Who can issue
A competent person with knowledge of water systems and Legionella risks. This can be the landlord themselves if they have sufficient understanding, but most landlords commission a specialist water hygiene company or a qualified Legionella risk assessor. The Legionella Control Association (LCA) maintains a list of member companies. Many gas engineers and property compliance companies also offer Legionella assessments.
Max fine
£20,000
Prison risk
Up to 2 years imprisonment under HSWA s.33 for serious breaches causing harm
Section 21
Does not block
1. Overview
A Legionella risk assessment evaluates the potential for Legionella bacteria to grow and spread in a property's water systems. Legionella pneumophila is the bacterium responsible for Legionnaires' disease, a severe form of pneumonia that can be fatal, particularly in elderly or immunocompromised individuals. The bacteria thrive in water stored between 20°C and 45°C, in stagnant water, and in systems with scale, rust, or biofilm — conditions commonly found in poorly maintained domestic hot water systems, especially those with storage tanks.
The Health and Safety Executive's Approved Code of Practice (ACOP L8) and HSG274 Part 2 guidance place a duty on landlords as duty holders to assess and control the risk of Legionella in their rental properties. While there is no specific law mandating a written Legionella risk assessment for domestic landlords, the Health and Safety at Work etc. Act 1974 and the Control of Substances Hazardous to Health Regulations 2002 (COSHH) create a legal duty to assess and manage risks to tenants' health from the water system. A failure to do so can result in prosecution with fines of up to £20,000 in the Magistrates' Court and unlimited fines in the Crown Court.
A standard domestic Legionella risk assessment covers the cold water storage tank (if present), hot water cylinder, boiler or immersion heater, all outlets (taps and showers, especially those infrequently used), any dead legs in the pipework (capped-off pipes that create stagnant water), and the water temperature at various points in the system. The assessor checks that the cold water is stored below 20°C, the hot water cylinder is set to at least 60°C, and that hot water reaches outlets at 50°C within one minute. Simple control measures — such as removing dead legs, insulating cold water tanks, and flushing infrequently used outlets — can significantly reduce risk.
2. Cost
A Legionella typically costs between £75 and £200. A standard domestic Legionella risk assessment costs £75–£150 for a typical house or flat. Larger properties, HMOs, or properties with complex water systems (multiple tanks, long pipe runs) cost £150–£200. Some compliance companies offer combined packages with gas safety checks and EICRs at a reduced rate. The assessment itself takes 30–60 minutes on site.
3. Regional Variations
England
The HSE's ACOP L8 and COSHH Regulations apply. Local authorities can prosecute under HSWA 1974. While there is no standalone Legionella regulation for domestic landlords, the duty of care is clear and enforceable. The HSE recommends risk assessments every 2 years, with annual reviews if conditions change. The HHSRS (Housing Health and Safety Rating System) includes Legionella as a Category 1 hazard.
Wales
The same HSE guidance and HSWA duties apply as in England. The Renting Homes (Wales) Act 2016 fitness for human habitation requirements implicitly include water safety. Welsh local authorities can use the HHSRS to assess Legionella risk as part of housing inspections. Rent Smart Wales training covers landlord obligations around water safety.
Scotland
The Health and Safety at Work etc. Act 1974 applies across Great Britain, so Scottish landlords have the same duties. The Scottish Housing Regulator expects compliance with water safety standards. Under the Repairing Standard, landlords must maintain plumbing in proper working order, which includes controlling Legionella risk. The Environmental Health function of Scottish local authorities can investigate and prosecute.
Northern Ireland
The Health and Safety at Work (Northern Ireland) Order 1978 applies, mirroring HSWA 1974. The HSENI (Health and Safety Executive for Northern Ireland) enforces compliance. The same ACOP L8 guidance is used. Legionella risk assessment obligations for landlords in Northern Ireland are functionally identical to those in England, Scotland, and Wales, though enforcement resources may differ.
4. Legionella by Location
Requirements and costs vary by local authority. Select your area for council-specific guidance.
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Start tracking your LegionellaFrequently Asked Questions
Do I legally need a Legionella risk assessment as a landlord?
The HSE's ACOP L8 states that if you are a landlord, you are a duty holder and must assess the risk of Legionella to your tenants. While there is no single regulation that says 'landlords must have a written Legionella risk assessment', the combination of HSWA 1974 and COSHH 2002 creates an enforceable obligation. If a tenant contracts Legionnaires' disease and you cannot demonstrate you assessed and controlled the risk, you face prosecution with significant fines and potential imprisonment.
How often should a Legionella risk assessment be done?
The HSE recommends every 2 years for standard domestic properties. However, a new assessment should be carried out whenever there is a change in the water system (new boiler, new pipework), a change in use of the property (conversion to HMO), or if the property has been vacant for an extended period. The assessment should be reviewed annually to check that control measures are still in place and effective.
Can I do the Legionella risk assessment myself?
Yes, if you are competent to do so. The HSE defines 'competent' as having sufficient training, knowledge, and experience. For a simple domestic property with a combination boiler (no stored water), the risk is low and a basic self-assessment using the HSE's landlord guidance may suffice. For properties with hot water cylinders, cold water tanks, or complex systems, a professional assessment is strongly recommended. The cost (£75–£150) is modest relative to the potential liability.
What are the main risk factors for Legionella in rental properties?
The highest risk factors are: water stored between 20°C and 45°C (hot water cylinder set too low or cold water tank in a warm loft), stagnant water in dead legs (capped-off pipes from removed appliances), infrequently used outlets (spare bathrooms, outside taps), cold water storage tanks without lids or insulation, and showerheads with limescale build-up. Properties with combination boilers and no stored water are generally lower risk.
What should I tell my tenants about Legionella prevention?
Provide written guidance (a simple information sheet) advising tenants to: run all taps and showers for at least 2 minutes weekly if not used regularly, not adjust the hot water thermostat (it should be set to at least 60°C), report any issues with water temperature or discoloured water immediately, and clean and descale showerheads every 3 months. This guidance should be included with the tenancy information pack and demonstrates you are actively managing the risk.