How Much Does a Legionella Risk Assessment Cost?

All three are, in a way. That is the problem.

Those six words are being used to sell three different things. A downloadable form. A proper visit from someone with a thermometer. A full commercial water hygiene survey. One name, three products.

Below is which is which, what you should expect to pay on a rented house, and what the cheap end quietly leaves out.

How much does a Legionella risk assessment cost?

A Legionella risk assessment costs £75 to £150 for a standard rental house or flat in the UK. Larger properties, HMOs and anything with stored water usually come in at £150 to £250. The visit itself takes about 30 to 60 minutes.

Those are market rates rather than a fixed tariff. You will see published guides quoting different figures, and there is a reason for that. Some are pricing domestic lets. Others are quietly pricing commercial buildings and not telling you.

Here is how it breaks down by property.

What you are having assessed	Typical market range
One-bed flat, combi boiler, no stored water	£75 to £120
Standard two or three-bed house or flat	£75 to £150
Larger house with a cylinder or loft tank	£150 to £200
HMO, or a flat on a communal water system	£150 to £250 and up
Booked in volume through a letting agent	£50 to £100
Portfolio, priced per property	Lower per unit than a one-off
Commercial premises	£300 to £1,000 and up

Two things worth noticing. The domestic numbers are modest. And if you have been quoted £400 for an ordinary rented house, you are being sold the wrong product.

Why the same job costs £9 in one place and £400 in another

Because three genuinely different jobs are sharing a name.

The £9 to £20 version: a form you fill in yourself

You answer questions about your own property online and a PDF comes back. Nobody visits.

I want to be fair about this. It is not a scam. The Health and Safety Executive says most landlords can assess the risk themselves, with no training or accreditation needed. So the logic behind the product is sound.

But you are buying a template and a document. You are not buying an inspection. Nobody has measured anything.

If your property is simple and you know it well, that may be enough. If it is not, you have paid £15 for a piece of paper based on your own guess.

The £75 to £150 version: someone actually turns up

A competent person comes to the property. They take the hot water temperature at the cylinder or boiler, and again at the taps. They check the cold is running cold. They look inside the tank if there is one, find the outlets nobody ever uses, and photograph what matters.

Then they write it up, date it, and tell you what to do about anything they found.

This is what most landlords picture when they ask the question. It is what the rest of this article is priced around.

The £300 and up version: commercial water hygiene

A different discipline entirely. It means an asset register, a system schematic, sentinel outlet readings and a written scheme of control. In a building with plant rooms and calorifiers, all of that is necessary and £450 is fair.

On a terrace in Acocks Green, it is overkill. Nine times out of ten, a landlord tells me the quotes made no sense. Usually they have collected one from each of these three worlds without realising.

What actually moves the price

Once you are comparing like with like, three things really shift the number.

Stored water is the big one

A combi boiler heats water on demand, so nothing sits around getting warm. That is the low-risk setup, and it is the quickest to assess.

A hot water cylinder or a cold water tank in the loft changes everything. Stored water sitting between roughly 20 and 45 degrees is exactly where Legionella is happy. More to check, more to write up.

Plenty of older Birmingham terraces have a tank up there. Most landlords do not know until someone goes and looks.

How many outlets there are

Every tap, shower and outside tap is a reading. A one-bed flat and a five-bed HMO are not the same afternoon, and they should not be the same price.

Whether the system is shared

Flats fed from a communal riser or a block tank need the shared parts considered too, not just your front door inwards. That is more work, and it is also where the real risk in a block tends to sit.

What you should get for the money

If a quote does not cover all of this, it is not really an assessment.

• Somebody attending the property in person
• Hot water temperatures at the cylinder or boiler, and at the outlets
• Cold water temperatures checked
• The water system identified and recorded: combi or stored, tank, cylinder, pipework
• Infrequently used outlets, dead legs and redundant pipework noted
• Tank condition and lid checked, where there is one
• Any thermostatic mixing valves noted
• Vulnerable occupants noted
• Photographs
• A written, dated record with the control measures in plain English The standards behind that are HSE guidance ACOP L8 and BS 8580-1, the British Standard for how the assessment should be done. You do not need to read either. Your assessor does.

Why there is no such thing as a Legionella certificate

This is the part that catches most landlords out, and it is worth being blunt about.

There is no legally recognised Legionella certificate. The HSE does not require one and does not recognise one.

Plenty of websites will sell you something that looks official. A border, a reference number, the lot. It carries no more weight than the assessment behind it.

What protects you is the dated written assessment, plus the invoice proving it was done. Keep both somewhere you can find them. To see how a properly photographed report looks, see examples of our work.

Does the price cover fixing whatever we find?

No, and this one catches people out too.

The assessment tells you where the risks are and what to do about them. Remedial work is a separate job at a separate cost. A missing tank lid. A showerhead that needs descaling. A dead leg that should come out.

On a normal domestic let there is usually very little to do, often nothing at all. But ask before you book, so the number you are quoted is the number you pay.

Can you do it yourself and pay nothing?

Legally, yes. The HSE says most landlords can assess the risk themselves, without being professionally trained or accredited. So the honest answer to "what does it cost" includes zero. You will not hear that from many people selling the service.

Here is where it goes wrong. A generic £15 template is not an assessment. It is a form.

Fill it in without measuring anything and what have you got? A document saying the property is fine, signed by the one person who benefits from that. If a tenant ever falls ill, that is the document you will be explaining.

When doing it yourself is fine

Combi boiler, no stored water, one bathroom, a property you know well. Buy a cheap thermometer, take the readings properly, write down what you found and date it. You are in a reasonable position.

When it stops being sensible

A cylinder or a loft tank. A communal supply. Several separate lets in one house. A property that sits empty for weeks at a time.

That is not me talking you into a booking. It is just where the risk lives. If you are still working out whether you need one at all, I have covered the landlord Legionella duty separately.

Does the price include testing the water?

Usually not, and usually you do not need it.

People use "testing" and "assessment" as though they mean the same thing. They do not. The assessment is the legal duty. Testing means sending a water sample off to a UKAS-accredited laboratory to look for the bacteria itself.

The HSE is clear on this. Sampling is not usually required for domestic hot and cold water systems. It is only needed in very specific circumstances.

If you do need it, budget £50 to £200 or more per sample, with laboratory fees on top. And if a quote for an ordinary rented house has routine sampling built in, ask why before you pay for it.

How often do you have to pay again?

Not every year, whatever the renewal email in your inbox says.

There is no fixed legal interval. The duty is to review the assessment when there is reason to think it is no longer valid. Industry practice, and my own recommendation, is roughly every two years. Sooner if the water system changes, if you have work done, or if the property has stood empty a long while.

At £75 to £150 every couple of years, that works out around £38 to £75 a year. Put it next to the gas safety certificate, the EICR and the EPC assessment you already pay for. It is normally the smallest line on the whole compliance calendar.

One more thing. A review should cost less than a first assessment. If it does not, ask what is being redone.

Four ways to bring the cost down

Book more than one property at a time. Portfolio assessments are priced per property and scheduled together. The travel gets shared, so the per-unit cost drops.

Use your agent's volume if you have one. Agents booking in bulk get the same effect. The published cost guides put agent-routed assessments around £50 to £100 a property. I would rather tell you that than have you find out afterwards.

Combine it with a visit that is happening anyway. We are usually in the property for the inventory, the check-in or a routine inspection. Doing the Legionella assessment on the same trip means one visit instead of two.

Have the property ready. Leave the heating and hot water on, because a cold system gives no useful reading. Make sure the loft hatch, airing cupboard and stopcock are reachable. Sort tenant access in advance. A smooth visit does not turn into a second one.

Can you claim it against tax?

Normally, yes. It is a running cost of letting the property. So it is generally an allowable expense against your rental income, the same as your gas safety check.

I am an inventory clerk, not an accountant, so check the detail with yours. Either way, keep the invoice. It is part of your evidence trail as much as your tax record.

What it costs you not to bother

This is the point where £100 stops looking expensive.

The HSE does not go round inspecting rented houses. Enforcement comes from the local authority instead, through the Housing Health and Safety Rating System under the Housing Act 2004. That means a hazard awareness notice, an improvement notice, or in serious cases a prohibition order.

Then there is the other side of it. Say a tenant falls ill and you cannot show you ever assessed the risk. Now you have a civil claim, and an insurer asking some very pointed questions.

You will see large fine figures thrown around on cost pages. I am not repeating them. I cannot verify one honestly for a residential let, and invented numbers are half the problem with this topic.

The real cost is simpler than a fine. You would be standing there trying to prove you did something sensible, with nothing written down.

What a Legionella risk assessment costs in Birmingham

Around the national average, which is the useful bit of news. London and the South East run well above it. We are not paying those rates here.

What varies locally is the housing stock. Much of what I inspect across Birmingham is Victorian and inter-war terraces. Plenty still have a cold water tank sitting in the loft. That is a longer job than a city-centre flat running off a combi.

Selly Oak and the student HMOs are their own category. One water system serving six or seven rooms, in a house that empties out completely for the summer. That long void is exactly the situation the HSE singles out. It is also the one landlords forget about.