A Legionella risk assessment completed several years ago can still be suitable if it reflects the building and its water systems today. Plumbing alterations, changes in occupancy and recurring monitoring problems can make earlier findings less reliable.
As 2026 draws to a close, facilities managers, landlords and Responsible Persons should check that their existing legionella risk assessment still reflects those changes. The start of 2027 does not, by itself, make a replacement assessment necessary.
Reviewing the position now can also highlight unresolved issues and help you decide which monitoring or maintenance work should take priority next year.
When Should a Legionella Risk Assessment Be Reviewed?
The law does not impose a fixed annual or two-year replacement cycle. The Health and Safety Executive’s Approved Code of Practice L8 states that assessments should be reviewed regularly, particularly when there is reason to suspect they are no longer valid.
Review intervals depend on the complexity of the water system, how the premises are used and the risks involved. A relatively simple system calls for a different approach from a large healthcare facility with extensive water distribution networks.
Reviewing an assessment does not necessarily mean commissioning a replacement. If the information remains accurate and existing controls are effective, a documented review may confirm that it is still suitable. Significant changes, however, may require a more detailed reassessment by a competent person.
What Changes Could Make Your Assessment Outdated?
Water systems can change between assessments without any obvious problems in day-to-day operation. Check the following situations against the changes made at your premises during 2026.
Plumbing Alterations or New Equipment
Installing pipework, relocating outlets or modifying hot and cold-water systems can affect water circulation and temperature control. Alterations may also leave redundant pipework connected, creating sections where water remains unused for extended periods.
Following refurbishment, check the legionella risk assessment and water-system schematic against the installed layout, particularly where outlets or pipework have been moved.
Changes in Building Occupancy
Partially occupied offices, closed hotel rooms and refurbished departments can have outlets that receive little use. Reduced water usage increases the potential for stagnation and can make existing flushing arrangements unsuitable.
Before a hotel reopens rooms after several months of closure, it should check that its control procedures still suit how those facilities will be used.
Changes to People Who May Be Exposed
An assessment should consider who could be exposed to contaminated water aerosols, including people who may be more susceptible to infection.
This is particularly important in healthcare and care settings, where changes in building use or occupant profiles may affect the precautions required. Control arrangements should reflect the people currently using the premises.
Recurring Monitoring Problems
Repeated temperature deviations, missed flushing checks or unresolved maintenance recommendations can indicate that existing controls need attention.
If several outlets repeatedly fail to achieve the required temperature conditions, investigate the cause and review the legionella risk assessment if the findings suggest that existing controls are no longer suitable. Recording the same problem month after month without corrective action does not demonstrate effective control.
Five Checks to Complete Before 2027
Start with the records you already have. Compare the assessment with monitoring results, maintenance records and building alterations to identify changes or outstanding issues that need attention.
- Check the assessment’s scope: Confirm that it covers the water systems, equipment and areas currently in use. Identify anything installed, modified or removed since the previous assessment.
- Review changes made during 2026: Examine plumbing alterations, refurbishment work, occupancy changes and periods when parts of the building experienced reduced water usage.
- Examine monitoring records: Look for recurring temperature problems, missed checks, infrequently used outlets and maintenance issues that remain unresolved.
- Confirm responsibilities: Check that the appointed Responsible Person and relevant personnel understand their duties, have appropriate training and can access current procedures.
- Review outstanding recommendations: Establish which actions have been completed, which remain open and whether any require further investigation.
If these checks identify significant changes or gaps in control, a competent person should determine the extent of any reassessment needed.
How Can an Updated Assessment Improve Legionella Control?
An up to date legionella risk assessment helps managers decide which control measures suit the system and where existing arrangements need attention.
Identifying infrequently used outlets can lead to revised flushing procedures. Recurring temperature problems can call for an investigation of the hot water system, while an inaccurate schematic can make relevant pipework harder to locate.
The findings should then inform the written control scheme, so monitoring, maintenance responsibilities and corrective actions reflect the risks identified.
Is Legionella Water Sampling Always Necessary?
Water sampling is not automatically required whenever an assessment is reviewed. For many hot and cold-water systems, temperature monitoring, inspections and maintenance records can provide appropriate evidence that control measures are working.
A legionella risk assessment helps determine when water sampling is appropriate, particularly where control effectiveness is uncertain or persistent problems need investigating. Different requirements apply to systems such as cooling towers and spa pools.
Testing should support the wider control programme rather than replace routine maintenance or corrective action. Results also need to be interpreted in the context of the system and its operating conditions.
Which Properties Should Multi-Site Managers Prioritise?
Multi-site managers need to prioritise buildings according to current risks and control concerns, not simply the date of the last assessment.
When scheduling legionella risk assessment reviews across multiple properties, give earlier attention to buildings with significant alterations, recurring monitoring problems or more vulnerable occupants.
A hotel reopening a previously closed accommodation wing may need attention sooner than an unchanged office with satisfactory monitoring records. A healthcare facility with repeated temperature failures needs prompt investigation even if its assessment is recent.
Where external contractors manage monitoring or maintenance, confirm that responsibilities are documented and findings reach the appropriate Responsible Person. Outstanding actions should be tracked until they have been addressed.
Prepare Your Legionella Compliance Plans for 2027
Use the year-end review to establish which water hygiene issues need attention in 2027. These priorities should come from changes to the system, monitoring findings and outstanding control actions.
Before confirming the maintenance schedule, check that recommendations from 2026 have been addressed or assigned, and that monitoring arrangements still suit the water systems in use.
Significant changes or weaknesses in control can call for updated procedures, maintenance, additional monitoring or reassessment. The action should reflect the finding and the risk involved.
Is Your Legionella Risk Assessment Still Up to Date?
If refurbishment, occupancy changes or recurring water temperature problems have affected your building during 2026, it is worth checking that your existing assessment still reflects the risks.
We can help you review existing Legionella controls, identify where further assessment or monitoring is appropriate and plan the next steps. Speak to Our Legionella Specialists