Legionella control for blocks of flats

A block is not a house. Stored water, shared plant and risers put it outside the low-risk presumption that covers most homes, and the duty for all of it sits with whoever manages the building.

Who holds the duty in a block

ACoP L8 places the duty on the person in control of the premises. In a block that is usually the freeholder, or the residents’ management company or right to manage company where one has taken on management. It covers the incoming main, the storage, the plant, the risers and everything else in the common parts. Pipework inside a flat is normally the leaseholder’s, and a leaseholder who sublets is a landlord with duties of their own.

HSE’s guidance is specific about agents. Where a managing agent is used, the management contract should say clearly who is responsible for maintenance and safety checks, including managing the risk from Legionella. Where it does not, the duty stays with whoever controls the premises and the water system in it. It is worth checking what your management agreements actually say.

Legionella and landlords

What makes a block different

Most houses are low risk because the water turns over every day and very little of it is stored. A block usually fails both tests.

Cold water storage tanks – Roof or basement tanks serving every flat, often sized for a demand the building no longer has.

Booster sets and break tanks – More stored water at the foot of the building, and pressure vessels where it can sit still.

Communal hot water – Central plant and long circulating runs, where a failing return temperature affects every flat on the riser.

Risers and service voids – Cold water gaining heat on its way up, in voids it shares with the heating pipework.

Empty flats – A void flat is a dead leg on a shared system, with nobody inside it running the taps.

Common-part outlets – Cleaners’ sinks, bin store taps and garden taps that are used once a month, if that.

The outlets you need are behind someone else’s front door

A monitoring regime depends on temperatures taken at sentinel outlets, the nearest and furthest points on each system. In a block those outlets are usually inside flats, and a managing agent has no automatic right to walk in and run a tap.

That is a design problem, not a reason to go without monitoring. A workable scheme combines what can be measured in the common parts and the plant room, such as tank temperatures and the flow and return on the hot water, with a small number of flats where access has been agreed in advance. The risk assessment should name those outlets and say what happens when access is refused.

Temperature monitoring

A roof tank is a small service reservoir

Tank, booster set, risers, outlets: the water system in a block is a distribution network in miniature, and it fails in the same ways. Water held too long warms up and loses quality. Storage sized for the wrong demand does not turn over. Whatever gets in at the tank reaches every tap below it.

Our background is in public water supply, where storage, turnover and water age are managed on networks serving whole towns. We bring the same questions to a block: how long the water sits, how warm it gets, and whether the storage still matches the building. Quite often the right answer is less stored water, not more flushing.

Our public supply work

Service charges change how the work is bought

Legionella control in a block is paid for through the service charge. It has to fit a budget that is set once a year, and it has to be explained to the people who pay it. A report listing forty defects at equal weight is no help with either. Remedial work needs to arrive prioritised and priced, so the urgent items can be done now and the rest can go into next year’s budget.

The consultation rules matter as well. Leaseholders have the right to be consulted on planned work that would cost any one of them more than £250, and on agreements lasting more than twelve months that would cost any one of them more than £100 a year. A tank replacement can pass the first threshold and a multi-year monitoring contract can pass the second. It is better to know that before the order is placed.

Records have to survive a change of agent

Blocks move between managing agents, and the water records are often what gets lost on the way. The incoming agent inherits the duty on day one, frequently with no risk assessment, no schematic and no temperature history to go with it.

HSE expects monitoring results to be kept for at least five years, and the risk assessment and control scheme for at least two years after they are replaced. We keep records in a form that can be handed over complete. When you take on a block without them, the first job is a baseline: what is there, what condition it is in, and what has to happen first.

Legionella control

We work with

Whoever carries the duty for the building.

Managing agents and block managers – One programme and one reporting format across the whole portfolio.

Residents’ management companies – Directors who are volunteers, and need the position explained plainly.

Right to manage companies – A baseline assessment at the point you take over management.

Freeholders and landlords – A clear line between your duties and those of your leaseholders.

Housing associations – Mixed-tenure blocks and sheltered schemes, where thermostatic mixing valves (TMVs) need servicing on schedule.

Facilities management providers – Water hygiene delivered inside a wider contract, to your reporting cycle.

One standard across every block.

Talk to us about a risk assessment, a tank clean and chlorination, TMV servicing, a monitoring programme across your portfolio, or a baseline for a block you have just taken on.

For any enquiries or questions please call: 01707 527 069