No — with only a mains-fed kitchen tap and a WC, you don’t need the thick, consultant-written survey a hotel or care home would commission. But you do still need a proportionate Legionella risk assessment. The duty to assess the risk doesn’t disappear just because there are no showers [1].

This catches out a lot of small businesses. You read that Legionnaires’ disease spreads through showers, spray taps and cooling towers, you look around a small office, and you reasonably conclude none of it applies to you. The risk in a kitchen-tap-and-WC office genuinely is low. The trap is treating “low” as if it means “nil” and skipping the part where you actually assess it and write that down.

So here is the honest answer, broken into the things small-business owners actually ask — and a plain description of what the bare minimum looks like.

The questions small-business owners actually ask

Do I need a Legionella risk assessment with no showers?

Yes, but a simple one. HSE is clear that for low-risk situations — its own example is a small building with a domestic-type hot and cold water system — a straightforward assessment by a competent person can be enough, and you may well find no further action is needed beyond keeping it under review [1][2]. What you cannot do is decide there is nothing to assess. The legal duty is to identify and manage reasonably foreseeable risk; “we looked and it’s low” is a perfectly valid conclusion, but only once you have actually looked and recorded it.

The absence of showers genuinely matters here, because showers are one of the main ways water becomes a breathable aerosol [3]. A tap filling a kettle and a WC cistern produce very little fine spray by comparison. That lowers the risk. It does not remove the duty to assess it.

Is a small business exempt from the Legionella rules?

No. There is no small-business exemption and no “too small to bother” threshold. The same general duty — assess and control the reasonably foreseeable Legionella risk in water systems you’re responsible for — applies whether you run a 2,000-desk headquarters or a two-person studio above a shop [1]. What changes with size and simplicity is the amount of work that is proportionate, not whether the duty exists. Simple premises earn a simple response. They do not earn a pass.

What counts as “low-risk” or “simple” premises?

Roughly: a small building on a mains supply, with a domestic-style hot and cold water system, no water sitting stored in tanks, no showers or other spray-generating outlets, water that turns over regularly, and nobody especially vulnerable on site [1][2]. An office where the only water is a kitchenette tap, a hand basin and a WC is the textbook example.

You drift out of “simple” the moment the system gains the features that let bacteria grow or spread: a cold-water storage tank, a hot-water cylinder holding tepid water, long dead legs of capped pipe, a shower, a spray tap, a water feature, or outlets that sit unused for weeks [3]. Any of those, and a do-it-yourself once-over is no longer obviously enough.

What does a simple assessment for an office with a kitchen tap actually involve?

Less than most people fear. A proportionate assessment of a genuinely simple water system follows the same logic as HSG274 [5], scaled right down — it is mostly looking, asking and recording:

  • Map the system. Note where water enters, the route to each outlet, the tap, basin and WC, and whether anything stores water. For most small offices this is a few lines, not a schematic.
  • Spot the risk features. Look for dead legs (a capped pipe to an outlet that was removed), a redundant water heater, anything holding standing water, and outlets that rarely get used.
  • Check the basics. Confirm hot water reaches the tap genuinely hot and cold stays cold, and that water moves through every outlet often enough not to stagnate [4].
  • Record the findings and the controls. Write down what you found, your conclusion that risk is low, the simple measures you rely on (regular use, the occasional flush of a little-used outlet), and a date to review.

That record is the assessment. It is the thing an inspector, an insurer or a buyer can ask to see, and the reason “we didn’t think we needed one” is a weak place to be standing.

We’re fully mains-fed with no stored water — doesn’t that remove the risk?

It lowers it a lot, which is exactly why your assessment is likely to be short. Mains-fed water that arrives cold, turns over regularly and leaves through a tap gives Legionella little chance to multiply, because the bacteria need warmth, stagnation and nutrients to build up [3][4]. No storage tank means no reservoir of standing water drifting up toward room temperature.

But “no stored water” is a control to verify, not a reason to skip the assessment. You still confirm there are no hidden dead legs, that a quiet back-room tap isn’t sitting idle for weeks, and that nothing warms the cold supply on its way through the building [4]. Those are the things a five-minute walk-round catches and an assumption misses.

Do I need to test the water or buy a Legionella certificate?

Almost certainly not, and be wary of anyone selling either as compulsory. Routine water sampling is not a general legal requirement for ordinary hot and cold water systems kept under good control — there is more on that in Is Legionella testing a legal requirement in the UK?. Nor is there a statutory “Legionella certificate” you must hold; what you need is the assessment plus evidence you are acting on it, which Do you need a Legionella certificate? What the law actually requires sets out in full. For a kitchen-tap-and-WC office, paying for annual lab tests is usually money better spent elsewhere.

Can I do it myself, or do I need a consultant?

For genuinely simple premises, a sensible owner or office manager can carry out and record the assessment themselves after reading the HSE guidance — the law asks for a competent person, not necessarily an external one [1]. The judgement call is being honest about complexity. If you are confident you understand your (very basic) system, do it and keep it under review. If there is a storage tank, a shower creeping into the floor plan, or you simply cannot tell whether that capped pipe matters, bring someone in. In-house vs professional Legionella risk assessments walks through where that line sits.

How often do I revisit it once it’s done?

Keep it under review rather than treating it as a one-off. Revisit whenever something changes — you take on extra space, fit a shower or kitchen, change how the building is used, have a long shutdown, or if a case of Legionnaires’ disease is ever linked to the premises [1][2]. For a stable simple office with nothing altered, a periodic re-read to confirm “still low, still controlled” is the proportionate rhythm. The point is that the assessment stays a live judgement, not a file gathering dust.

A caveat before you file it away

This is general guidance, not a verdict on your building. Whether your premises really is “simple”, and whether a self-done assessment is genuinely enough, depends on what is behind your walls — and I cannot see that from here. If you have any doubt about a tank you’d half-forgotten, a dead leg, a vulnerable occupant, or a spray outlet, treat that doubt as a prompt to get a competent person to look. None of this is legal or medical advice; it is the framework, applied through a site-specific assessment.

If you only do one thing

Don’t leave the question hanging. Spend twenty minutes walking the premises with a notepad: list every water outlet, note whether anything stores water, flag any pipe or tap that is rarely used, and write down that you found the risk low and why. That single dated, signed sheet is a defensible simple assessment — far stronger than an empty “we assumed we didn’t need one”. If you want the reasoning behind it first, Legionella risk assessment basics: what it is and why you need it covers what an assessment is for. Then keep that sheet where you can produce it, and set a reminder to revisit it the day anything about your water system changes.

Sources

[1] HSE, “Legionnaires’ disease - what you must do”. https://www.hse.gov.uk/legionnaires/what-you-must-do/index.htm [2] HSE, “Legionella and landlords’ responsibilities”. https://www.hse.gov.uk/legionnaires/legionella-landlords-responsibilities.htm [3] HSE, “Systems most likely to create legionella risk”. https://www.hse.gov.uk/legionnaires/risk-systems.htm [4] HSE, “Hot and cold water systems”. https://www.hse.gov.uk/legionnaires/hot-and-cold.htm [5] HSE, “Legionnaires’ disease: Technical guidance (HSG274)”. https://www.hse.gov.uk/pubns/books/hsg274.htm