Call for Greater Thermal Efficiency in Retrofits Amid Commercial-to-Residential Applications Boom

As planning applications for commercial-to-residential permitted developments (PD) surge dramatically, architects are urged to prioritise the thermal efficiency of retrofitted components to ensure sustainable and comfortable living spaces.

04.04.2025

Recent government statistics reveal that commercial-to-residential permitted developments have reached an unprecedented high in the latest quarter, marking a significant increase of over one third compared to the previous year ending September 2024.¹

With this in mind, polymer solutions supplier REHAU is highlighting the need to review all components fitted during the conversion process and their impact on the property’s overall energy efficiency.

“The housing crisis is a hot topic across industries, and finding solutions is becoming increasingly urgent,” says Martin Hitchin, CEO of REHAU UK. “Commercial-to-residential conversions offer intriguing possibilities in this space, and it is heartening to see this rise in applications for PDs.

“While this is encouraging news, architects must focus beyond the application process and prioritise the best possible specification practices for key property components, including window selection. This is especially important given the pressure to decarbonise the country’s housing. The UK’s residential sector contributes 18% of the nation's total carbon emissions,² and thermally efficient components are crucial for reducing this figure in line with net zero goals.”

Progress towards this goal can already be seen in the social housing sector, where seven housing associations have joined forces to maximise the impact of £31m in grants given under the Warm Homes: Social Housing fund to modernise properties.

Led by Places for People and comprising of Accent, Eddystone Housing, Thrive Homes, Papworth Trust, Paradigm, and the West Kent Housing Association, the Thriving Communities Consortium aims to deliver retrofitting at scale and save customers up to £500 on their annual bills.

The growing importance of retrofitting existing properties further emphasises the need to identify cost-effective components that cost-effectively impact a building’s thermal performance. As explored in REHAU’s latest whitepaper, Retrofit Right – Making Social Housing More Energy-Efficient, carrying out well-informed ‘medium retrofits’ – fitting high-quality frames on existing properties – can markedly improve a property’s overall thermal performance.

“Windows and door systems are prominent sources of heat loss within any property,” Martin concludes. “Yet this can be turned on its head, as informed component specification can empower architects to identify cost-effective solutions that can significantly impact a building’s overall energy efficiency.

“Whether upgrading social housing or converting commercial properties for residential use, third-party expertise is key to effectively decarbonise current and future homes. Retrofitting offers great potential for future housing, and architects that leverage supply chain knowledge will stay ahead of the curve as PD applications increase and building work intensifies.”

Click on the link to download REHAU’s latest report, ‘Retrofit Right – Making Social Housing More Energy-Efficient’