Do You Legally Need a Legionella Risk Assessment?
The short answer: almost certainly yes — but it's far simpler and cheaper than most people fear. Here's the plain-English version.
If you're responsible for a building with a water system that other people use, you need a Legionella risk assessment. It's a legal duty under the Health and Safety at Work etc. Act 1974 and COSHH 2002, set out in the HSE's ACOP L8 and HSG274. It applies to landlords, businesses, holiday lets and almost any premises with a hot and/or cold water system. You do not need to hire a consultant: for an ordinary hot and/or cold water system you can carry out the assessment yourself, provided you're competent.
If you're responsible for a building that other people use — as a landlord, a business owner, or in any similar role — and it has a hot and/or cold water system, you have a legal duty to assess and control the risk of Legionella bacteria. This surprises a lot of people, because unlike a gas safety check, nobody really tells you about it. So let's clear it up.
What the law actually says
The duty comes from the Health and Safety at Work etc. Act 1974 and the Control of Substances Hazardous to Health Regulations 2002 (COSHH). The Health and Safety Executive's Approved Code of Practice, known as ACOP L8, and its technical guidance HSG274, explain how to meet that duty. Together they say: if you control premises with a water system, you must assess the risk of Legionella and take practical steps to control it.
The important bit: the legal duty is to assess and control the risk — and, in most cases, to keep a record of what you've done. That's it. It's a duty to think it through properly and act, not a duty to spend a fortune.
Does this apply to me?
It applies far more widely than people expect. You have a duty if you're responsible for a premises with a water system used by others — whether you rent out a single flat, run a small business, manage a holiday let, or look after any building the public or staff use. The common thread is simply: a water system, and someone legally responsible for it. The type of building barely matters; the duty is the same.
Do I have to pay a professional to do it?
No — and this is the part that saves you the most money. For an ordinary hot and/or cold water system, you can carry out the assessment yourself, provided you're competent — meaning you understand what you're looking at and what to do about it. The law is clear that most people responsible for ordinary systems can do this themselves and don't need to be professionally accredited.
What needs a professional isn't decided by the size of the building — it's decided by what's in it and what the assessment turns up. A cooling tower, a spa pool, or a healthcare setting is outside a self-serve assessment. So are specific hands-on jobs — plumbing or electrical work, or anything needing specialist access — and anything the site's own risk assessment flags as beyond routine control. Short of those, an ordinary hot and/or cold water system is one you can assess and monitor yourself, whether it's a single flat or a large multi-site estate.
The "Legionella certificate" myth: you may have been told you need a "Legionella certificate". You don't — the HSE recognises no such thing. If a letting agent or anyone else asks for one, what they actually mean is a risk assessment. Don't pay for a certificate that doesn't officially exist.
What happens if I just ignore it?
The risk isn't only illness — though Legionnaires' disease is serious and can be fatal. It's also legal. If someone is exposed to a risk you failed to assess and control, you can face enforcement action or prosecution, even if nobody actually falls ill. Keeping a simple, honest record of your assessment and the steps you take is what protects you.
So — does this apply to you?
If you're in control of premises with a water system that other people use, then yes — the duty is almost certainly yours. The law calls you the duty holder, and it's deliberately broad: landlords (any let, from a single flat to an HMO), employers, business owners, building owners, and managing agents all fall under it. You can appoint someone to help with the day-to-day, but the responsibility itself can't be handed off — it stays with you.
So the honest answer to the question at the top of this page is: for most people who own or run a building others use, yes, you legally need a Legionella risk assessment — and it's far more manageable, and far cheaper, than the industry has ever made it look. That's exactly the gap EASYlegionella was built to close: it guides you through your own assessment, in plain English, built around your building — so meeting the duty stops being something you pay a fortune for or put off, and simply becomes a straightforward task that can be easily delegated if required.
Do it yourself, properly — for a fraction of the cost
EASYlegionella guides you through your own Legionella risk assessment and keeps your monitoring on track, step by step, in plain English.
Join the launch listThis guide is general information to help you understand your responsibilities, not legal advice, and does not certify compliance. Your legal duty as the responsible person cannot be transferred. Always refer to HSG274 Part 2 and ACOP L8 for the authoritative guidance.