Projects

"AES have provided valuable support in navigating the complexities of the overheating regulations across our London developments. Their expertise in dynamic thermal modelling and detailed understanding of Part O and GLA requirements enabled us to confidently progress with fully compliant, energy-efficient designs. Their clear communication, proactive approach, and tailored strategies helped us overcome acoustic and ventilation challenges while maintaining internal comfort for future residents. We look forward to working with AES on future projects." 

Devlin Coulton, Head of Technical, Barratt East London  

Project Details

Barratt London is a well-established home builder with over 30 years of experience delivering high-quality residential developments across London.  

They approached us for support with Part O Overheating assessments on several London-based projects. These developments included multiple residential blocks where window opening was restricted due to acoustic constraints, creating additional complexity in meeting overheating standards.  

With London’s dense urban fabric and the intensifying heat island effect, the city faces some of the most stringent overheating requirements in the UK. Our assessment methodology helped Barratt London navigate these challenges and ensure compliance with both Building Regulations Part O and the Greater London Authority (GLA) guidance, aligning with their commitment to building sustainable and regulation-compliant homes. 

How We Met the Requirements

To support Barratt London’s compliance with Building Regulations Part O and GLA guidance, AES undertook a comprehensive overheating assessment across several multi-block developments in London.  

Sample apartments were carefully selected to represent worst-case scenarios, based on factors such as orientation, acoustic restrictions, and security considerations. This ensured a robust and representative analysis of the developments’ thermal performance.  

AES carried out detailed Part O assessments using industry leading dynamic thermal software and the industry-recognised CIBSE TM59 methodology. To manage solar gains, especially on upper floors and areas with higher solar exposure, we proposed differentiated G-values for glazing. This allowed for more effective solar control without compromising daylight or design quality.  

Where window opening was restricted, AES recommended ventilation systems capable of tempering incoming air. This solution maintained internal comfort conditions and supported full compliance with Part O and the GLA requirements - without relying on active cooling systems. The approach also offered the potential to reduce energy consumption and operational carbon, aligning with sustainability goals.  

Key Deliverables: 

• CIBSE TM59-compliant overheating analysis using dynamic thermal modelling 

• Compliance with Part O and GLA guidance 

• Glazing recommendations (G-values) 

• Tailored ventilation strategy proposals 

• Solutions that enhance comfort while supporting energy efficiency and sustainability objectives 

Outcome

As a result of our assessments and recommendations, all developments successfully met the requirements of Approved Document O and the Greater London Authority’s overheating guidance. This enabled Barratt London to progress their schemes with confidence, ensuring regulatory compliance while supporting their commitment to delivering comfortable, energy-efficient homes across London.