Understanding legionella risk assessment costs helps you budget effectively and avoid overpaying. Prices vary significantly based on property type, complexity of water systems, and the assessor you choose. This guide breaks down what to expect and how to get good value.
What type of property needs assessment?
This affects the typical cost range.
What affects the cost?
Several factors determine how much you'll pay for a legionella risk assessment.
Property size and type
The most significant factor is the size and complexity of your property:
- Single residential property — Simple hot and cold water systems, typically one boiler, few outlets
- Small commercial premises — More outlets, possibly multiple water heaters or a stored water system
- Large commercial buildings — Multiple floors, complex distribution systems, potentially dozens or hundreds of outlets
- High-risk premises — Hospitals, care homes, hotels with cooling towers or spa facilities
Water system complexity
Complex systems take longer to assess and require more expertise:
- Simple systems — Combination boiler, mains-fed cold water, few outlets
- Stored water systems — Cold water storage tanks, hot water cylinders
- Complex systems — Multiple risers, dead legs, infrequently used outlets, mixed-use buildings
- High-risk systems — Cooling towers, evaporative condensers, spa pools, dental chair units
Geographic location
Prices vary by region:
- London and South East — Typically 20-40% higher than average
- Major cities — Slightly above average
- Rural areas — May include travel charges
- Scotland and Northern Ireland — Broadly similar to English regions
Assessor qualifications and experience
More experienced assessors may charge more but provide better value:
- Legionella Control Association (LCA) members — Industry body with quality standards
- City & Guilds qualified assessors — Formal training and certification
- UKAS accredited laboratories — For water sampling services
- Years of experience — Particularly valuable for complex systems
Typical costs by property type
Residential properties (landlords)
| Property Type | Typical Cost | What's Included |
|---|---|---|
| Single flat/apartment | £50-100 | Basic assessment, written report |
| Single house (2-3 bed) | £75-150 | Full assessment, schematic, recommendations |
| HMO (small) | £100-200 | Assessment of shared facilities, multiple outlets |
| HMO (large/complex) | £150-350 | Detailed assessment, complex shared systems |
| Portfolio discount | 10-30% off | Multiple properties assessed together |
What affects residential costs:
- Number of bathrooms and kitchens
- Type of water heating (combi vs stored hot water)
- Age and condition of plumbing
- Presence of water storage tanks
- Whether sampling is required
Many landlord-focused services offer legionella assessments from around £50-75 for straightforward properties. However, ensure the service includes a proper site visit — desktop-only assessments may not meet legal requirements.
Commercial properties
| Property Type | Typical Cost | Complexity Factors |
|---|---|---|
| Small office (fewer than 10 employees) | £150-300 | Few outlets, simple system |
| Medium office (10-50 employees) | £250-500 | Multiple floors, more outlets |
| Large office (50+ employees) | £400-1,000+ | Complex systems, multiple risers |
| Retail shop (small) | £150-300 | Staff facilities, customer toilets |
| Retail (large/multiple floors) | £300-700 | More extensive systems |
| Restaurant/café | £200-400 | Kitchen systems, customer facilities |
| Warehouse | £200-500 | Depends on welfare facilities |
| Light industrial | £250-600 | Process water may increase complexity |
High-risk and complex systems
| System Type | Typical Cost | Why It's Higher |
|---|---|---|
| Care home (small) | £400-800 | Vulnerable occupants, detailed assessment |
| Care home (large) | £800-2,000+ | Extensive systems, high stakes |
| Hotel (small) | £500-1,000 | Guest rooms, potentially complex |
| Hotel (large) | £1,000-3,000+ | Hundreds of outlets, cooling towers |
| Hospital/healthcare | £1,500-5,000+ | Critical systems, compliance requirements |
| Cooling tower system | £500-1,500 | Specialist knowledge required |
| Spa/swimming pool | £400-1,000 | Additional water treatment systems |
| Dental practice | £300-600 | Dental unit waterlines |
If you have cooling towers, evaporative condensers, or spa pools, ensure your assessor has specific experience with these high-risk systems. Generic assessors may miss critical risks.
What's included in the price?
A proper legionella risk assessment should include:
Always included
- Site visit — Physical inspection of your water systems
- System schematic — Diagram showing water distribution
- Risk identification — All potential legionella risks documented
- Risk evaluation — Assessment of likelihood and severity
- Control recommendations — Specific actions to manage risks
- Written report — Formal documentation for compliance
Sometimes included (check before booking)
- Written scheme of control — Detailed ongoing management plan
- Temperature monitoring records — Template for ongoing monitoring
- Training — Brief overview for responsible person
- Re-assessment — Follow-up review at agreed interval
Usually extra cost
- Water sampling/testing — Laboratory analysis for legionella (£50-150 per sample)
- System schematic drawing — Detailed CAD drawings for complex systems
- Tank inspection — Internal inspection of storage tanks
- Remedial works — Any physical improvements needed
- Ongoing monitoring service — Regular temperature checks and management
Basic vs Comprehensive Assessment
Basic Assessment
- •Site visit and inspection
- •Written risk assessment report
- •List of recommendations
- •Suitable for simple residential properties
Comprehensive Package
Recommended- •Everything in basic assessment
- •Written scheme of control
- •Monitoring record templates
- •System schematic diagram
- •Better for commercial and complex properties
Bottom line: For straightforward residential properties, a basic assessment may suffice. For commercial premises or complex systems, the comprehensive package provides better ongoing compliance support.
How to get value for money
Get multiple quotes
For anything beyond a simple residential property, get at least three quotes. Provide each assessor with the same information:
- Property address and access arrangements
- Type of business/use
- Approximate number of water outlets
- Type of water heating system
- Any known complexity (tanks, multiple buildings, etc.)
Check what's included
The cheapest quote isn't always best value. Check whether each quote includes:
- Site visit (not just desktop assessment)
- Written scheme of control
- System schematic
- Any follow-up support
Consider ongoing costs
The initial assessment is just the start. Factor in:
- Re-assessment — Required every 2 years or when systems change
- Monitoring — Monthly temperature checks (can be done in-house)
- Annual review — May need professional review
- Water sampling — If recommended, ongoing testing costs
Portfolio and multi-site discounts
If you have multiple properties:
- Ask about portfolio discounts (10-30% typical)
- Consider annual service contracts
- Batch properties in the same area together
- Some providers offer subscription models
Warning signs of poor value
Be cautious of:
- Very low prices — May indicate corner-cutting or inexperience
- No site visit — Desktop-only assessments rarely meet legal requirements
- Generic reports — Should be specific to your property
- No qualifications stated — Assessors should have relevant training
- High-pressure sales — Legitimate assessors don't need to pressure you
The purpose of a legionella risk assessment is to protect people from a potentially fatal disease. While cost matters, the cheapest option may leave you with inadequate protection and potential legal exposure.
DIY vs professional assessment
Can you do it yourself?
Legally, you can conduct your own legionella risk assessment if you're competent to do so. However, "competent" has a specific meaning — you must have sufficient training, knowledge, and experience.
DIY may be suitable if:
- Very simple property (single residential let with combination boiler)
- You have relevant training (water hygiene qualification)
- Low-risk water systems with no storage
Professional assessment recommended if:
- Commercial or multi-occupancy premises
- Complex water systems
- Stored water (tanks, cylinders)
- Vulnerable occupants (care home, nursery, healthcare)
- You're unsure about system layout or risks
- You need the report for insurance or compliance evidence
Cost comparison
| Approach | Initial Cost | Ongoing Cost | Risk Level |
|---|---|---|---|
| DIY (with training) | £200-500 training | Your time | Higher if inexperienced |
| Professional (basic) | £50-300 | Re-assessment fees | Low |
| Professional (comprehensive) | £150-1,000+ | Service contract | Lowest |
Frequently asked questions
Risk assessments should be reviewed at least every 2 years, or sooner if there are significant changes to your water systems, building use, or occupancy. Some assessors offer re-assessment at reduced rates. You don't always need a full new assessment — sometimes a review and update is sufficient.
Not necessarily. Very cheap assessments may involve desktop-only reviews without a site visit, generic template reports, or assessors without proper qualifications. A proper assessment requires a physical site visit and should be specific to your property. Check what's included before booking.
For landlords, legionella risk assessment costs are typically an allowable expense against rental income. For businesses, it's a normal operating expense. Consult your accountant for your specific situation.
The assessment will include recommendations for addressing any issues found. Remedial works are typically separate from the assessment cost. Common issues include installing thermostatic mixing valves, removing dead legs, or improving temperature control — costs vary widely depending on the work needed.
Water sampling and laboratory testing is sometimes recommended but not always required. Testing is more likely to be needed for complex systems, if there's been an outbreak, or if the risk assessment identifies specific concerns. Budget £50-150 per sample if testing is recommended.
Look for assessors who are members of the Legionella Control Association (LCA), hold City & Guilds water hygiene qualifications, or work for companies with relevant accreditations. Experience matters too — ask how many assessments they've done on properties like yours.
Next steps
Ready to book your legionella risk assessment? Here's what to do:
- Gather information — Property address, type of water heating, approximate number of outlets
- Get quotes — Contact 2-3 assessors for comparable quotes
- Check credentials — Verify qualifications and experience
- Book the assessment — Allow 1-2 weeks lead time for scheduling
- Prepare for the visit — Ensure access to all water systems
Related guides:
- What is a legionella risk assessment? — Understand what's involved
- Do I need a legionella assessment? — Check your legal obligations
- What is legionella? — Understand the disease and risks
Need a legionella risk assessment for your property? A qualified water hygiene specialist can provide a tailored quote and ensure you meet your legal obligations.