---
title: "How much does a Legionella risk assessment cost in the UK?"
source_url: https://legionella.io/articles/how-much-does-a-legionella-risk-assessment-cost-in-the-uk/
canonical_url: https://legionella.io/articles/how-much-does-a-legionella-risk-assessment-cost-in-the-uk/
pillar: "Legionella Risk Assessment"
summary: "A flat per-property quote rarely fits. See the real drivers behind UK Legionella risk assessment cost so you can scope the survey before you ask for prices."
primary_keyword: "Legionella risk assessment cost"
date_published: 2026-01-27
date_reviewed: 2026-06-26
author: "Legionella.io editorial team (REMOTE TECH LTD)"
reviewed_against: "HSE L8 and HSG274 guidance"
region: "United Kingdom"
license: "(c) REMOTE TECH LTD. Quote freely with attribution and a link to source_url."
---

# How much does a Legionella risk assessment cost in the UK?

There is no single price, and any company that gives you one over the phone without asking about your building is guessing. A Legionella risk assessment is priced on what your water system actually contains: outlets, plant, complexity and access. A small shop with a kitchenette and a care home with a calorifier plant room sit at opposite ends of the same quote sheet.

So the useful question is not "what does it cost" but "what in my building moves the number". Get that straight and you can read three quotes side by side instead of picking the cheapest and hoping.

The legal duty behind the survey is fixed: if you control premises, you must assess the risk from Legionella, and you are expected to use a competent assessor to do it [1]. What varies is the effort that competent assessment takes on your specific site.

## What you are actually paying for

A risk assessment is a person walking your system, asset by asset, against the methodology in BS 8580-1 and HSG274 [2][3]. They tally outlets, identify dead legs, check stored and distributed temperatures, photograph plant, map the system into a schematic and write up the risk. The bill is mostly skilled time on site plus the report afterwards.

That framing matters because it tells you why two buildings of the same floor area can quote very differently. Time on site tracks the number of things to inspect and how hard they are to reach, not the square footage.

## The cost breakdown: what really drives the number

Think of the quote in three layers. There is the planned spend you can predict from your own building. There is friction cost that comes from how awkward the site is to survey. And there is the failure cost of buying a survey too thin to rely on.

**Planned drivers (you can estimate these yourself):**

- **Outlet count.** The single biggest lever. Each tap, shower, drinking point and infrequently-used outlet is a thing to find, log and assess. A site with 12 outlets and one with 120 are not in the same price band, regardless of floor area.
- **Number and type of systems.** A cold-water-only premises with a mains-fed kitchen is quick. Add a stored hot water calorifier, a TMV blending circuit, a cold water storage tank, a shower bank or any evaporative plant and each adds assessment scope.
- **Number of buildings or floors.** Separate plant rooms, multiple risers and detached blocks each need their own walk-round and schematic.
- **Report depth and asset register.** A basic compliant report costs less than one that also delivers a full asset register, labelled schematics and a written scheme of control ready to drop into a logbook.

**Friction drivers (these inflate a quote quietly):**

- **Access.** Tenanted flats, occupied hotel rooms, secure wards or ceiling-void plant all slow the survey and sometimes need a second visit.
- **Schematic state.** No existing drawings means the assessor builds the system map from scratch, which is slow.
- **Asbestos, confined space or working-at-height.** Plant rooms with these constraints need extra control and competence and push the rate up.
- **Mobilisation and travel.** A remote single site carries more cost per outlet than a cluster the assessor can survey in one trip.

**Failure cost (the part the cheapest quote hides):**

- A survey that undercounts outlets or skips the schematic leaves you with an action plan you cannot price or defend. You pay again to redo it, and in the meantime your records do not match your system. In my view this is where most "cheap" assessments actually cost the most.

## What it typically costs

The figures below are illustrative planning bands drawn from typical published UK market rates, not a quote for your building. They move with the drivers above — chiefly outlet count, the number and type of systems, and how awkward the site is to survey — so read them as the shape of the market rather than a price you can hold anyone to.

- **A small, simple, low-risk single premises** — a shop, a small office, a handful of outlets on a mains-fed system — typically sits at the bottom of the market, illustratively somewhere around £150 to £350.
- **A mid-sized building** with stored hot water, a calorifier or TMVs and a few dozen outlets usually lands in the middle, illustratively in the region of £350 to £700.
- **A large, complex or multi-building site** — hundreds of outlets, several plant rooms, or a healthcare-type estate — runs into four figures, illustratively from around £1,000 and into several thousand for the biggest estates.

Your outlet count and system list, not your postcode, decide where you land. Because scope varies this much, the only number you can rely on is a current written quote built against the same outlet-and-system brief given to every supplier — ask for that rather than a figure over the phone.

## Where the spend pays back

The assessment is the cheapest document in the whole compliance chain, and it sets the cost of everything after it. A precise outlet count and a clean schematic mean your monitoring, flushing and remedial work are scoped correctly the first time. A vague one means duplicated visits, mispriced remedials and an audit trail with gaps.

The pragmatic call: pay slightly more for an assessor who delivers a usable asset register and schematic, because those become the backbone of your ongoing logbook. A flat-rate "tick the box" survey saves a little now and costs you in every monitoring cycle that follows. For the in-house-versus-professional side of that decision, see [In-house vs professional Legionella risk assessments](https://legionella.io/articles/in-house-vs-professional-legionella-risk-assessments/), and for sequencing the actions the survey produces, [Justifying Legionella control measures: cost vs risk](https://legionella.io/articles/justifying-legionella-control-measures-cost-vs-risk/).

## How to justify it internally

Frame the assessment to finance as the document that prices everything else, not as a standalone cost. It is also the evidence that you assessed the risk at all, which is the baseline legal expectation [1]. Spending a little more for a complete, structured report reduces the cost of monitoring, the cost of an audit and the cost of getting it wrong.

When you request quotes, give every supplier the same scope: approximate outlet count, list of systems (cold storage, stored hot water, TMVs, showers, any cooling plant), number of buildings and whether usable schematics exist. Quotes built on the same scope are comparable. Quotes built on a guess are not.

This is general guidance to help you scope and compare quotes; it does not set a price for your building or replace the judgement of a competent assessor working to BS 8580-1 on your actual system, whose findings and review frequency are driven by what they see on site rather than any figure here [2][4].

A concrete step today: walk your premises and write down every water outlet and every piece of plant you can see, then mark which schematics you already hold. That single list will get you tighter, more comparable quotes than any phone call, and it drops straight into a digital logbook as the start of your asset register rather than living on a clipboard that the next assessor cannot find.

## FAQ

### Why is one quote half the price of another for the same building?

Usually because the scope differs, not the building. The cheaper quote may assume fewer outlets, skip the schematic, deliver a thinner report or budget a single visit where your access needs two. Compare what each includes, not just the bottom line, and give both suppliers an identical outlet-and-system list before you decide.

### Does the assessment need redoing every year, and is that an annual cost?

Not on a fixed annual clock. A full reassessment is generally driven by change to the system, the occupancy or the findings, with reviews to confirm it remains valid in between, and the frequency is set by your risk assessment rather than a set schedule [4]. Budget for review effort yearly and a fuller reassessment when something material changes.

### Is a cheap online or remote Legionella risk assessment good value?

For anything beyond a very simple low-risk premises, treat a desk-based or self-completed survey with caution. The expectation is a competent assessment of your actual system, and an outlet count or dead leg cannot be verified from a form [1]. The saving disappears the moment you re-survey to fill the gaps.

## Related reading

- [Legionella risk assessment basics: what it is and why you need it](https://legionella.io/articles/legionella-risk-assessment-basics-what-it-is-and-why-you-need-it/)
- [In-house vs professional Legionella risk assessments](https://legionella.io/articles/in-house-vs-professional-legionella-risk-assessments/)
- [Justifying Legionella control measures: cost vs risk](https://legionella.io/articles/justifying-legionella-control-measures-cost-vs-risk/)

## Sources
[1] HSE, "Legionnaires' disease - what you must do". https://www.hse.gov.uk/legionnaires/what-you-must-do/index.htm
[2] BSI, "BS 8580-1:2019 - Risk assessments for Legionella control. Code of practice". https://knowledge.bsigroup.com/products/water-quality-risk-assessments-for-legionella-control-code-of-practice-1
[3] HSE, "Legionnaires' disease: Technical guidance (HSG274)". https://www.hse.gov.uk/pubns/books/hsg274.htm
[4] HSE, "Legionnaires' disease. The control of legionella bacteria in water systems - ACoP and guidance (L8)". https://www.hse.gov.uk/pubns/books/l8.htm