Reoccupation After Close Down Across the UK
When a building or part of a building has been closed for an extended period, water in the system can stagnate, temperatures can drift into the wrong range and conditions that favour Legionella growth can develop.
Before people return, it’s important to complete reoccupation water safety checks so that hot and cold water systems are brought back into safe use in a controlled way.
The Testing Lab PLC (TTL) helps dutyholders across England, Scotland and Wales to plan and deliver reoccupation checks after shutdowns, closures and periods of very low occupancy.
More Informaton
More Information
Safe reoccupation of buildings after shutdown
Buildings may be closed or operating at minimal occupancy for many reasons, including:
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Planned closures (refurbishment, seasonal shutdowns, holidays)
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Unplanned closures (fire, flood, structural issues)
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Events like Covid-19 lockdowns and other restrictions
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Partial closures where certain wings, floors or facilities are mothballed
During these periods, water systems often:
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Are used infrequently or not at all
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Sit at temperatures that allow Legionella bacteria to multiply
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Accumulate sediment, biofilm and corrosion products
Reoccupation checks provide a structured way to assess and manage the risk before staff, residents, patients and visitors come back into the building.
Why closed buildings increase Legionella risk
Legionella bacteria thrive in:
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Stagnant or low-flow water
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Water temperatures between roughly 20°C and 45°C
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Systems with nutrients such as scale, rust and organic matter
In normal operation, regular water usage, temperature control and routine monitoring help keep these risks under control. When a building is closed down:
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Outlets are not used, so water stagnates in pipework
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Heating and cooling may be turned down or off, allowing temperatures to drift
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Flushing and routine checks are often reduced or stopped
That’s why HSE and industry guidance emphasise the need to review and manage Legionella risks before reoccupation, not afterwards.
When to plan reoccupation water safety checks
You should consider a reoccupation water safety check when:
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Buildings or systems have been closed, mothballed or on very low use for around two weeks or longer
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Parts of a site (wings, blocks, annexes, plant rooms) have been isolated or taken out of routine use
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Major changes have been made to water systems during the closure
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There is any doubt that routine monitoring and flushing regimes have been maintained
Ideally, reoccupation checks are planned before closure as part of your water management policy. However, if a closure has already happened, it’s still essential to complete appropriate checks before people return.
If you are planning to reoccupy a building after a shutdown, or if you need help assessing a system that has been unused for some time, please contact our experienced and dedicated team:
Tel: 0800 177 7264
Email: info@thetestinglab.eu
Or please complete our online call back form or use the “Call Me” button, and we’ll respond promptly.
Our reoccupation water safety service
TTL’s reoccupation service is built around Legionella control, your existing risk assessment and water management policy. We typically:
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Review the length and nature of the shutdown
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Assess what was done (if anything) to manage water systems during closure
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Plan a reoccupation check programme for your hot and cold water systems and any other risk systems
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Carry out site-based checks and actions before reoccupation
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Provide a clear summary of what has been done and any follow-up actions required
We work closely with your responsible person, estates/maintenance team and, where applicable, your health & safety, infection control or facilities management teams.
Typical checks and actions we carry out
The exact scope depends on your building, systems and risk assessment, but a reoccupation visit commonly includes:
Who we work with
We support reoccupation planning and checks for:
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Offices, commercial and retail premises
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Schools, colleges and universities
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Care homes, supported living and healthcare settings
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Local authority and social housing stock
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Industrial and manufacturing sites
Whether you are dealing with a single building, a campus or a multi-site portfolio, we can build a reoccupation approach that matches your assets and risk profile.
Why choose The Testing Lab PLC for reoccupation after close down?
Legionella and water management specialists
Risk assessments, water management policies, monthly monitoring and reoccupation checks from one provider.
Practical, site-based support
Technicians who understand how water systems behave in real buildings, not just in theory.
Consistent documentation
Clear, audit-ready records of what has been checked, when and by whom, to support regulatory and internal assurance.
Independent. Nationwide.
Supporting clients across England, Scotland & Wales from our National Control Centre in Doncaster.
Integration with wider services
Ability to link reoccupation checks with ongoing monitoring, training and remedial works so your controls stay effective.
Areas we cover
We provide reoccupation water safety checks and wider water management services across:
- Yorkshire & Humberside
- North East & North West
- East Anglia & East Midlands
- London, South East & South West
- West Midlands, Scotland & Wales
We can support one-off reoccupation projects or integrate reoccupation planning into your ongoing water management and monitoring programme.
Frequently asked questions about reoccupation after close down
Our Accredited Testing Services
Thank you very much for the air sampling results – and please accept our grateful thanks for resolving this issue so quickly and for the promptness of the report.
Your analyst, Lee, was very helpful and his suggestions and advice appreciated.
We would have no hesitation in recommending The Testing Lab and will be in touch soon with regards arrangements for a full asbestos survey for the rest of the site.
TTL have been working directly as my analyst for the last 12 months on a very complex asbestos removal scheme, they have achieved all of their KPI’s without fail and on a number of occasions surpassed their SLA in acting for us on planning issues associated with the demolition in regard to contamination which cannot be removed as part of the normal sequence of operation.
There reports are always issued within timescales and they have policed the reports by the Licensed asbestos contractor faultlessly sometimes in very difficult circumstances.

