A legionella risk assessment looks at a building's water system and asks where Legionella bacteria could grow and reach someone's lungs: water sitting between 20 °C and 45 °C, water that does not move, and outlets that make a fine spray. In the UK, anyone who controls premises — employers, landlords, managing agents — has a duty to assess that risk and control it, and the Health and Safety Executive's Approved Code of Practice L8 and its guidance HSG274 describe how. This template records the system, the risk factors and the temperatures you actually measured, and flags every reading outside its target. You can fill it in here and download a finished PDF without creating an account.
Who needs one
Any employer or person in control of premises with a water system people use. That includes workplaces, hotels, care homes and schools, and it includes residential landlords: a landlord renting out a flat with a combi boiler still has to consider the risk, even if the assessment is short and the conclusion is that the risk is low.
The law does not require a certificate, and there is no such thing as a "legionella certificate" for a domestic let. What it requires is that the risk is assessed by someone competent, that sensible controls are in place, and that you can show it. A completed, dated assessment with readings is how you show it.
What the temperatures should be
The targets below are the ones commonly used under HSG274. Your written scheme may set its own; use those where it does.
- Cold water at an outlet — below 20 °C within two minutes of running.
- Hot water at an outlet — at least 50 °C within one minute of running (55 °C in healthcare premises).
- Hot water stored in a cylinder or calorifier — at least 60 °C.
- Hot water returning to a calorifier on a circulating system — at least 50 °C.
- Cold water in a storage tank — below 20 °C.
Where the risk hides
Most findings come from the same few places. Outlets that are hardly used — a spare bathroom, a cleaner's sink — let water sit warm in the pipe for weeks. Dead legs, lengths of pipe left in place after a fitting was removed, do the same permanently. Showers spray water as a fine mist and collect scale where bacteria can live. Cold water tanks without a proper lid gather dust, insects and worse. Properties left empty between lets let the whole system stagnate.
The form asks about each one. Where something is present and not controlled — no weekly flushing, a lid that does not fit, a dead leg still in place — it becomes a finding with its own corrective action.
Why this form does not say "compliant"
L8 is a code of practice, not a checklist that a building passes. Following it is one way to meet the legal duty; another approach can be just as good if it controls the risk as well. A form that stamped a building "L8 compliant" would be claiming more than one visit can know. This one records what the system is, what was found, what was measured and what has to happen next — which is what an inspector or an insurer will ask to see.
Speak while you walk, and the document writes itself: read each thermometer aloud as you go from tap to tap, and the temperature log fills in, outlet by outlet.
Common questions
Do landlords need a legionella risk assessment?
Yes. Residential landlords in the UK have a duty to assess and control the risk from legionella in the properties they let. For a typical flat or house with a combi boiler and no stored water the assessment is short and the risk is usually low, but it still needs to be done and recorded.
Can I do the assessment myself?
Yes, if you are competent to do it — you understand the water system and the risk factors. Many landlords assess simple domestic properties themselves. Larger or more complex systems, and premises with vulnerable people, usually call for a specialist.
How often should it be reviewed?
The law does not set a fixed interval. Review it regularly, and straight away if the system changes, the use of the building changes, the people using it change, or monitoring shows the controls are not working. Many duty holders review every one to two years.
Do I need to test the water for legionella?
Not routinely in most domestic and simple systems — temperature checks are the usual evidence that control is working. Sampling for bacteria is used in higher-risk systems, such as cooling towers, spa pools and healthcare buildings, or when temperatures cannot be maintained.
What is a sentinel outlet?
The outlets nearest to and furthest from the hot water heater or cold tank on each part of the system. If those reach the right temperatures in time, the rest of that part of the system is likely to as well, which is why monthly checks usually start with them.