Guide · Water Hygiene
Communal water systems in flats: whose risk assessment is it?
A landlord letting a flat in a converted house or purpose-built block controls only part of the water system serving the tenant: the pipework inside the flat, downstream of communal tanks, risers and sometimes shared hot water plant that belong to someone else. Water hygiene here is a boundary question — and unmanaged boundaries are where the gaps live.
Water Hygiene
Who holds the water hygiene duty in a shared building?
Everyone with control of part of the system, for their part: the freeholder or management company for communal tanks, risers and shared plant; the flat landlord for the installation within the demise and for the tenancy's overall risk assessment; managing agents for whatever their appointment delegates. The duty follows control, and control is split by the lease.
The flat landlord's assessment cannot stop at the front door in one crucial sense: it should identify what the flat's water arrives from — mains direct, communal cold storage, shared hot water — because the risk profile inside the flat depends on it. Assessing the flat while ignoring its supply is describing a tap and calling it a system.
Water Hygiene
What should a flat landlord actually find out about the building?
The system basics: whether cold water is mains-fed or tank-fed from communal storage, whether hot water is generated in-flat or supplied from central plant, and who manages the communal side under what regime. The managing agent or freeholder should be able to answer in a paragraph — and the request itself is evidence of diligence.
Then the paperwork: whether a communal water risk assessment exists, when it was reviewed, and whether monitoring or maintenance it prescribes actually happens. A landlord is entitled to ask, service charges typically fund it, and the answers belong — even as a one-line summary with dates — in the flat's own compliance file.
Water Hygiene
What does the in-flat assessment cover in this context?
The demise's own system, in the light of its supply: outlets and their use, any in-flat storage (rare but real in conversions), dead legs from refurbishments, showerhead condition, temperatures at the taps — with hot water temperature doubling as a check on central plant where heat arrives communally. Simple findings, but anchored to the building's reality.
Occupancy patterns matter as they do everywhere: a flat standing empty between tenancies stagnates regardless of how well the freeholder runs the tanks, so void flushing and pre-tenancy routines remain the flat landlord's own controls. The communal assessment protects the supply; only the flat's regime protects the last few metres.
Water Hygiene
What happens when the communal side is neglected?
The flat landlord escalates in writing: to the managing agent or freeholder, identifying the concern — no assessment, missed monitoring, tank condition — and requesting action, with the correspondence retained. Leaseholders funding management through service charges have standing to insist that safety obligations funded by those charges are performed.
Persistent failure has formal routes — the lease's machinery, recognised tenants' associations, tribunal challenges to management standards — but most cases resolve well before them, because a written water-hygiene query is easy to answer and awkward to ignore. What the flat landlord must not do is nothing: known supply-side neglect, undocumented and unchased, becomes part of their own risk picture.
Water Hygiene
How do records flow between the parties?
Ideally as summaries in both directions: the communal assessment's conclusions and monitoring confirmations flowing to flat owners on request or with service-charge reporting, and — where central plant serves the flats — anything anomalous found in-flat (persistent tepid hot water, discolouration) reported upward promptly, since one flat's reading is the building's data.
The flat's compliance file holds the stitched-together picture: the in-flat assessment, the supply summary, the correspondence trail, void routines and temperature checks. When a tenant, council or insurer asks about water safety, the answer spans both sides of the boundary — and the file that can show both halves is the one that closes the question.
Water Hygiene
Do purpose-built blocks and conversions differ?
In typical configuration, yes: modern purpose-built blocks trend toward mains-boosted cold supply and in-flat combi heating — systems storing little communally — while older blocks and house conversions carry the legacy arrangements: roof tanks over the top flat, shared cylinders, gravity systems with generous storage. The older the building, the more the communal side usually matters.
Conversions add ambiguity as well as tanks: leases drawn casually, management informal or absent, and nobody clearly holding the communal duty. A landlord buying into a small conversion should treat the water system's ownership and regime as a due-diligence question alongside the roof and the freehold — because in a two-flat house, 'the freeholder's problem' may effectively mean theirs.
Water Hygiene
What does the well-managed boundary look like?
Each side documented and each side aware of the other: the communal system assessed and monitored by whoever controls it, the flat assessed by its landlord in the light of its supply, summaries exchanged, anomalies reported both ways, and voids managed in-flat regardless. No gap, no duplication — the boundary managed like the party wall it is.
The underlying principle serves every shared-building duty, not just water: split control demands explicit allocation, and explicit allocation demands paperwork. Landlords who get the water hygiene boundary right usually find they have simultaneously mapped the fire, electrical and structural boundaries too — same lease, same parties, same discipline.
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FAQ
Related questions, answered
What does the written assessment include?
A description of the water system, identified risk points, the control measures in place or recommended, tenant advice, and the assessor's details and date — your evidence that the duty has been considered properly.
What simple controls reduce legionella risk?
Hot water stored at 60°C or above, cold water kept cold, flushing outlets after void periods, descaling and cleaning showerheads, and insulating or removing redundant pipework. The assessment records which of these apply to your property.
Who can carry out the assessment in your area?
A competent person — which for a simple domestic system can be the landlord themselves if they understand the water system, or a contractor for assurance and documentation. Complex systems with tanks and long pipe runs justify professional assessment.
What if I ignore legionella duties?
The duty sits under the Health and Safety at Work etc. Act framework, so serious failures can be enforced by the HSE or your local council and prosecuted, with fines set by the courts. In practice, risk to tenants and insurance exposure are the immediate concerns.
How often should the assessment be reviewed?
When there is reason to think it is out of date — for example changes to the water system, a change of use, or evidence controls aren't working. Periodic review is good practice; the law sets no fixed interval for domestic rentals.
What should tenants be told about legionella?
Simple advice: run showers and taps that haven't been used for a week or more before normal use, keep showerheads clean, and report water system problems. Giving this guidance in writing is an easy control measure to evidence.
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