Designing a school, office or healthcare facility without air conditioning? You’ll likely need a TM52 Overheating Assessment. But how much should you budget for it? Costs for TM52 assessments vary but understanding the factors that influence pricing can help you plan better, save time, and stay compliant.

In this blog, we’ll break down how much a TM52 assessment costs, what’s included, and how Gradwell Group delivers exceptional value with no hidden surprises.

What is a TM52 Overheating Assessment? 

A TM52 Assessment is used to assess overheating risk in non-domestic buildings like schools, offices, and hospitals especially those without mechanical cooling.

Developed by CIBSE (Chartered Institution of Building Services Engineers), TM52 evaluates if indoor temperatures exceed comfort limits using dynamic thermal modelling.

The results help ensure:

• Comfortable, safe indoor environments
  
  
• Planning approval compliance
  
  
• Support for BREEAM credits and sustainable design goals
  
  

If you’re new to TM52, check out our guide on the difference between TM59 and TM52.

How Much Does a TM52 Assessment Cost?

Typical TM52 assessment cost in the UK:

Project Type                                                 Cost Estimate (ex. VAT)

Small office or single-zone                 £225 – £300

Medium school/commercial                £300 – £500

Large, multi-zone building                   £500 – £800+

At Gradwell Group, we provide tailored quotes based on your building’s specifics, not generic packages. That way, you only pay for what you need.

What Affects the Price of a TM52 Assessment?

The cost depends on several key factors:

1. Building size and number of zones

Larger buildings with more occupied spaces require more simulation time and data modelling.

2. Design complexity

Unusual shapes, mixed-use spaces, or complex ventilation strategies take longer to model.

3. Level of detail required

Projects aiming for BREEAM, WELL or Passivhaus standards may require deeper reporting and compliance checks.

4. Turnaround time

Need results fast? A priority service may add a small premium.

What’s Included in a TM52 Assessment?

At Gradwell Group, your TM52 assessment includes:

• Full dynamic thermal modelling
  
  
• Analysis of all 3 TM52 criteria
  
  
• Use of CIBSE weather data files
  
  
• Clear, illustrated compliance reports
  
  
• Mitigation advice if zones fail
  
  
• Unlimited support via phone/email
  
  

We can also combine TM52 with Part O, SAP Calculations, or EPCs to save you time and money.

Explore our TM52 Assessment Service

How to Get an Accurate Quote?

We offer free consultations to review your plans and provide a precise quote. To get started, just send us:

• Floorplans and elevations
  
  
• Glazing specs and insulation values
  
  
• Ventilation strategy
  
  
• Occupancy profile
  
  

Once we have the drawings and key details, we’ll turn around your quote in 24 hours or less.

Contact us now to request your free, no-obligation quote.

Can You Save on TM52 Assessments?

Yes! Here’s how to keep your costs down:

• Bundle with other services (like SAP, SBEM, EPCs or TM59)
  
  
• Plan early fewer design changes means less rework
  
  
• Use standard design elements to reduce modelling time
  
  
• Work with experienced assessors who won’t waste hours on guesswork
  
  

According to the UK Government, improved thermal design can cut cooling costs by up to 40% in schools and offices.

Why Choose Gradwell Group?

We’ve worked with architects, planners, developers and schools across the UK, offering:

• Efficient assessments with fast turnaround
  
  
• Clear reports planners understand
  
  
• Real design advice, not just data dumps
  
  
• Fair pricing no hidden costs
  
  

Don't just tick a box future-proof your design with expert overheating modelling that supports planning success.

FAQs

1: What’s the minimum I can expect to pay?

Small, single-zone buildings may start around £600+VAT, depending on scope.

2: Are discounts available for multiple assessments?

Yes. ask us about bundle pricing for TM52 + Part O or SAP calculations.

3: How quickly can you deliver the report?

Usually within 5 to 10 working days, or faster for urgent projects.

4: Is a TM52 assessment cheaper if I already have TM59?

‍

It can be. We may reuse some modelling elements and just send us both briefs.

Get the Best Value for Your Build

TM52 assessments are becoming a key part of planning submissions across the UK. The cost isn’t fixed but with the right team, it can be affordable, fast, and stress-free. At Gradwell Group, we don’t just help you pass we help you design better, cooler, more sustainable buildings. Let’s make your project a success starting today. Get a free quote now or explore our TM52 services.