Part O - Overheating Calculations
Lincoln, Lincolnshire & East Midlands

Our Services – Part O Overheating Calculations 

At AirMetric, we help builders, developers and design teams ensure new residential properties are comfortable, compliant and future-proof. Our Part O Overheating Calculations service is designed to assess and mitigate the risk of overheating in line with current UK Building Regulations.

 

What are Part O Overheating Calculations?

Part O calculations assess the risk of excessive indoor temperatures in new residential buildings. The assessment ensures dwellings are designed to limit unwanted solar gains and provide adequate means of removing heat.

Compliance is required under Building Regulations Part O, which applies to new residential buildings in England.

There are two routes to compliance:

• Simplified Method – based on glazing limits, orientation, and cross-ventilation criteria.

• Dynamic Thermal Modelling (TM59) – detailed modelling used for more complex designs, high-risk locations, or where the simplified method is not suitable.

The assessment considers factors such as:

• Glazing size and orientation

• Solar gains

• Shading devices

• Ventilation strategy

• Location and external noise constraints

 

Why Choose Part O Calculations?

Regulation compliant – ensures your project meets mandatory overheating requirements.

Reduces redesign risk – identify overheating issues early in the design stage.

Supports planning and Building Control approval.

Improves occupant comfort – protects residents from excessive indoor temperatures during summer months.

 

What We Provide:

Assessment using the Simplified Method or Dynamic Thermal Modelling, as required.

Review of glazing, shading and ventilation strategy.

Clear guidance on mitigation measures if required (e.g. reduced glazing, solar control glass, external shading, purge ventilation improvements).

A professional compliance report suitable for Building Control submission.