Overheating Assessments | TM52 & TM59 Compliance Reports

Overheating Assessment

What Is an Overheating Assessment?

An overheating assessment evaluates your building’s risk of becoming uncomfortably or dangerously hot in summer, using approved dynamic thermal modelling techniques. Under Part O, new dwellings must be designed to limit internal temperatures and prevent excessive heat gain.

The assessment considers:

Solar gains through glazing
Window size, orientation and shading
Ventilation rates (natural or mechanical)
Thermal mass and insulation levels
Occupancy patterns
Internal heat gains

If the model predicts excessive temperatures, the design must be altered to comply.

Why Overheating Compliance

Why Overheating Compliance Matters

Overheating isn’t just inconvenient—it can cause serious health issues, especially for vulnerable occupants. Modern buildings with large glazing elements or inadequate ventilation are particularly at risk.

Part O aims to:

Protect occupant wellbeing
Ensure homes remain comfortable in warm conditions
Minimise heat build-up in summer
Reduce risk of heat-related illness
Encourage sustainable design solutions

Without a compliant Overheating Report, Building Control will not sign off your development.

Why Choose

Why Choose Home Energy EPC for Your Overheating Assessment?

We provide fast, accurate and highly detailed modelling backed by years of experience in energy and building compliance.

What We Offer:

Dynamic thermal modelling using approved CIBSE TM59 methodology
Full Part O compliant assessment and reporting
Clear, practical design recommendations
Fast turnaround times
Combined packages (SAP + Part O + Ventilation + Air Tests)
Experience with single plots through to large multi-unit developments

Our aim is to prevent costly redesigns by identifying compliance issues early.

What’s Included

What’s Included in an Overheating Assessment?

Our assessments follow government-approved modelling frameworks and include:

Detailed Review of Architectural Drawings

We examine building orientation, glazing ratios, layout and shading.

Thermal Modelling (TM59)

Dynamic modelling simulates temperature changes throughout the day and year.

Assessment Against Part O Requirements

We test your building for:

Maximum allowed temperature thresholds
Overheating hours exceeded
Night-time purge ventilation

Shading & Ventilation Analysis

We assess overhangs, balconies, blinds, window opening angles and mechanical ventilation.

Alternative Compliance Options

If your design doesn’t pass, we recommend:

Solar control glazing
External shading
Increased natural ventilation
Reducing glazed areas
Mechanical cooling where necessary

Full Overheating Report for Building Control

Your final report includes all modelling data, inputs, results and recommended actions.

Who Needs

Who Needs an Overheating Assessment?

Part O applies to:

All new-build residential dwellings
Houses and flats with large glazing areas
Buildings exposed to high solar gain
Conversions that create new dwellings

Developments in dense urban areas or south-facing properties are especially likely to require detailed modelling.

Take

How Long Does an Overheating Assessment Take?

Most assessments are completed within 3–5 working days, depending on project complexity. Faster turnarounds can be arranged for urgent applications.

We work directly with your architect or design team to gather required data and minimise delays.

Common Issues

Common Issues We Identify

Many designs fail Part O due to:

Excessive glazing on south/west elevations
Poor ventilation strategies
No shading systems planned
Inadequate openable window area
High internal heat gains

We offer practical, low-cost solutions to fix these issues.

How to Prepare

How to Prepare for Your Assessment

We require the following documents:

Architectural drawings (plans/sections/elevations)
Window schedule with U-values and g-values
Ventilation strategy (natural/mechanical)
Site location and orientation
Construction specifications

Once received, we begin modelling immediately.

Offer

Pricing

Our Overheating Assessments are competitively priced and can be bundled with:

SAP Calculations
Water Efficiency Calculations
BREL Reports
Ventilation Testing
Air Tightness Testing

Discounts available for multi-plot developments.

let’s make it shine!

Book Your Overheating Assessment Today

Ensure your new build meets Part O requirements and provides comfortable, safe living spaces for future occupants.

info@homeenergyeepc.co.uk

0121 000 0000

Book your Part O overheating assessment today and keep your development fully compliant with Building Regulations.

Overheating Assessments by Home Energy EPC