Legionella Risk Assessment Cost in 2026: Landlord & Business Guide (UK)

Legionella is one of the most overlooked duties in property and facilities management, right up until someone asks for the risk assessment. If you’re an employer or in control of premises with a water system, you have a legal duty to assess and control the risk. Here’s what a legionella risk assessment costs in 2026, who actually needs one, and how to choose the right provider.

Do I legally need a legionella risk assessment?

Yes, if you’re a duty holder. The duty comes from the Health and Safety at Work etc. Act 1974 and the Control of Substances Hazardous to Health Regulations 2002 (COSHH), with the practical detail set out in the HSE’s Approved Code of Practice L8 and technical guidance HSG274. In plain terms, if you’re an employer or in control of premises with a water system, you must assess the risk of legionella and manage it. You can read the detail in our guide to ACOP L8 and HSG274.

Landlords: separating the duty from the myth

This is where a lot of confusion, and a fair bit of mis-selling, creeps in. The honest position is this. Landlords do have a duty to consider and control legionella risk, because the same health and safety law applies to let property. But for most ordinary domestic rentals the risk is low, the assessment is simple, the landlord can carry it out themselves, and there is no legal requirement for an annual “certificate”, for water testing, or for a paid contractor. Anyone selling you a mandatory yearly “landlord legionella certificate” is selling you something the law does not ask for. What the law does ask for is a suitable assessment, kept under review, and actually recorded. The picture is different for HMOs, blocks of flats with communal or stored water systems, and larger or commercial premises, where a fuller professional assessment is genuinely warranted.

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Legionella risk assessment cost in 2026

Typical UK prices (excluding VAT):

The single biggest cost driver is the water system. The more storage tanks, cylinders, outlets and dead-legs a building has, the longer the assessment takes and the more it costs.

How much does legionella testing cost?

Testing is not the same as a risk assessment. The assessment is the legal duty. Testing means taking water samples and sending them to a lab, and HSE says it is not usually needed for domestic hot and cold water systems. It is used for higher-risk systems such as cooling towers, spa pools and some care or healthcare settings, or where the assessment calls for it. The price depends on how many samples are needed and the visit to take them, so ask for a quote that shows both.

In London? See legionella risk assessors in London, or start with our legionella risk assessment guide. Running a spa pool or hot tub? Read our guide to HSG282.

What a good assessment actually covers

• A schematic of the water system and identification of risk points (tanks, calorifiers, little-used outlets, showers).
• Temperature checks, hot water hot enough and cold water cold enough.
• An assessment of who’s at risk, especially vulnerable occupants.
• A written scheme of control and a clear action plan with review dates.

How to choose a legionella and water hygiene provider

• Membership of the Legionella Control Association (LCA) is the recognised marker of a competent provider or company. On My Safety Consultant, LCA members show an LCA chip, and you can check any firm on the LCA register yourself.
• Individual membership of the Water Management Society (WMSoc) is a good sign of an individual assessor’s competence and continuing development.
• Independence. Ideally the assessor isn’t automatically selling you the remedial works they recommend.
• Clear scope and review dates. The assessment should be a living document with defined review dates, not a one-off PDF.

Browse water hygiene and legionella providers across the UK, check for the LCA chip, and contact them directly with no lead fees.

Frequently asked questions

How much does a legionella risk assessment cost for a rental property?

For a typical single domestic rental, expect roughly £90–£200 (average around £145), or £50–£100 per property if arranged in bulk through a letting agent. Remember that for most simple domestic lets you are allowed to carry out the assessment yourself.

How often should it be reviewed?

There’s no fixed “annual” legal interval. The assessment must be reviewed regularly and whenever something changes in the water system or its use. Two years is a common review cycle for lower-risk premises, sooner for higher-risk ones.

Do landlords legally need one?

Landlords must assess and control legionella risk, but for most domestic lets this is a simple, proportionate assessment kept under review, which the landlord can do themselves. There is no legal requirement for an annual certificate or water test.

What qualification should the assessor have?

Look for membership of the Legionella Control Association (LCA), individual membership of the Water Management Society, and experience with your type of water system.