REHAU FHS_Report Cover (High Res) - 1118439

Future-Proofing Social Housing with Better Window Retrofits

As the UK targets net-zero emissions by 2050, decarbonising social housing is crucial. The incoming Future Homes Standard (FHS) will accelerate this, but its complexities present significant challenges for local authorities.

23.12.2024

Mark Gajda, Head of Technical Services and Certification Manager at REHAU UK, highlights key steps for compliance in retrofitting housing stock.

The FHS has already disrupted the social housing sector, with tightening adjustments to Building Regulations in 2022 over ventilation and energy efficiency requirements placing local authorities under pressure. Yet regardless of the upheaval, the objective remains the same – reducing residential emissions in line with net zero targets.

However, with 80% of current properties set to be still in use by 2050,¹ and most public housing being built between 1945 and 1980,² retrofitting great swathes of existing building stock will undoubtedly be challenging. Effective and swift upgrading will require close collaboration with LA supply chains, especially given sector hopes for efficient allocation of the Social Housing Decarbonisation Fund by the new Labour government.

Preparing for 2025

The need for joined-up processes and greater education of the FHS is made clear in REHAU's latest market report, Future Homes Standard: Preparing UK Housing for 2025. It revealed that over two-thirds of the 200 housebuilding decision-makers the organisation surveyed for the report felt unprepared for the new standards, and 79% find the FHS timeline challenging.

This sense of confusion has been undoubtedly compounded by the December 2023 FHS consultation, which did not lower the required 1.2 W/m²K u-value for frames. At face value, keeping this thermal performance metric unchanged may look like a reprieve for the sector. However, focusing only on u-values may cause stakeholders to miss the broader benefits of the Home Energy Model (HEM).

Holistic Approach with HEM

Replacing the outdated SAP10, the HEM evaluates energy efficiency by assessing peak energy use and local weather patterns, allowing flexibility in component specification. As different homes have unique requirements based on location, accounting for this was seen as more practical than having a more static measuring model for key components that impact building ventilation and thermal efficiency, including windows.

But despite their vital role, awareness of FHS-compliant frame systems is low. REHAU’s whitepaper found 65% of respondents could not identify a compliant frame system, highlighting the need for supply chain cooperation to find solutions. This knowledge gap is likely to have repercussions in areas outside newbuilds, including retrofitting and futureproofing existing homes.

Sector Readiness

Sector concerns could already be seen before the December 2023 consultation. Specifically, REHAU's report survey showed that 76% of respondents working on new builds found the 2025 timeline challenging, citing issues around cost, supply chains and insufficient technical understanding.

Previous government revisions to energy efficiency standards have also raised doubts within the sector about what best sustainability practice looks like. Though the election may ease some concerns on this issue, new policies could further complicate the landscape for both new builds and retrofit projects.

Collaboration and Innovation

Indeed, clarity is key for local authorities, where public ownership of social housing increases pressure to meet rigorous energy standards. In this fast-moving landscape, stakeholders must ensure window systems comply with upcoming standards and assessment models. Consequently, leveraging supplier expertise is key when retrofitting properties.

By collaborating more closely, specifiers can choose the most efficient frames for different locations in line existing and upcoming legislation and assessment models. Engaging experts at the project design stage can also ensure better-informed specification practices and compliance with thermal performance and ventilation requirements.

With uncertainty surrounding the FHS’s implementation and the recent change in government, it is essential the sector is proactive when addressing upcoming challenges – including retrofitting frames. Consulting component providers about regulatory requirements and their impact on building fabric is crucial, and by adopting a holistic approach, the industry can retrofit thermally efficient social housing fit for the future. Despite the complexity regulations present, with the right partnerships and innovation, the sector can decarbonise existing social housing stock and achieve net zero goals.

To read REHAU’s report, Future Homes Standard: Preparing UK housing for 2025, click here.