Enerphit is the Passivhaus standard for retrofits that achieve thermal insulation similar to Passivhaus's new-build levels.

The project involved fitting Eurocell’s Modus 75mm profile windows to the houses. These triple-glazed windows achieve a U-value of 0.8 and significantly reduce heat loss, helping the homes meet strict energy efficiency targets.

The windows were specified for their high thermal performance and their ability to be recycled at the end of their lifespan. The PVC-u frames were reprocessed into new window profiles.

The closed-loop recycling process, implemented by Eurocell and Asset Fineline, meant the old PVC-u windows, once removed, were collected, recycled, and manufactured into new frames.

Eurocell already has a well-established PVC-u recycling facility. The “closed-loop” aspect is that the removed PVC-u windows were collected, recycled, and turned into new window profiles for future projects.

While the old windows from this specific project were not directly remanufactured into the ones installed here, the new windows used in the retrofit also contain a significant percentage of recycled PVC-u, maintaining a continuous cycle of material reuse.

This initiative supports the council's goal of achieving net zero operational energy, where energy consumption equals renewable energy produced on-site, as part of the government’s £3.8bn Warm Homes: Social Housing fund.

The project significantly reduced waste and embodied carbon, aligning with the council's sustainability goals. Saint-Gobain supported the project through its Glass Forever programme, recycling end-of-life glass and producing high-performance glazing to complement the Modus window system.

Eurocell plans to partner with more organisations in future to complete more fully closed loop projects like this.