The Future Homes Standard sets a new performance bar for new-build housing, and secondary glazing has no direct role in meeting it, since it applies to construction that doesn’t yet have a window fitted, let alone one needing a secondary layer. That distinction matters, because it’s the reason this topic gets misunderstood by specifiers working across both new-build and retrofit portfolios.
What the Future Homes Standard does change is the wider regulatory direction of travel, and that has real consequences for how existing building stock, including listed and heritage property, gets treated going forward.
What the Future Homes Standard Actually Covers
The Future Homes Standard is part of the government’s Building Regulations reform programme, raising the energy efficiency and carbon performance requirements for new homes built in England. It sits within the same regulatory family as Building Regulations Part L, which governs thermal performance and energy efficiency, but applies specifically to new dwellings rather than existing buildings undergoing refurbishment.
Because secondary glazing is, by definition, a retrofit product added to an existing primary window, it sits outside the direct scope of the Future Homes Standard. A new-build property meets its thermal performance requirements through the specification of its original windows, typically double or triple glazed sealed units, not through a secondary system added afterward.
Where the Direction of Travel Matters for Existing Stock
The Future Homes Standard’s significance for specifiers working on existing buildings is indirect but real. It signals where minimum acceptable thermal performance is heading across the built environment as a whole, and that trajectory has consistently pulled Part L requirements for existing buildings upward alongside it, along with related policy such as the 2030 EPC targets for social housing and Minimum Energy Efficiency Standards for the private rented sector.
Facilities managers, housing associations, and architects working on refurbishment programmes should expect the performance bar for existing stock to keep tightening in the same direction the Future Homes Standard sets for new build, even though the specific regulation governing their project is Part L rather than the Future Homes Standard itself.
Why Listed and Heritage Buildings Sit Outside the New-Build Standard
Listed buildings and those in conservation areas are typically exempt from the full force of Part L thermal requirements, in recognition of the fact that meeting a new-build thermal standard would often require altering the historic fabric that gives the building its protected status in the first place. The Future Homes Standard, targeting new construction specifically, has no bearing on this exemption.
That exemption doesn’t remove the practical pressure to improve thermal performance where it can be achieved without altering protected fabric. Historic England guidance explicitly recommends secondary glazing as the preferred intervention precisely because it delivers thermal and acoustic improvement without the alterations that would conflict with a building’s listed status. Granada’s Horizontal Sliding system, for example, achieves a U-value of 1.5 W/m²K with 4mm Low-E glass and an 80mm cavity, a meaningful improvement over the single glazing typical of pre-war heritage stock, delivered without touching the original window.
Specifying Secondary Glazing Within This Regulatory Context
For specifiers working on refurbishment or retrofit programmes, the practical takeaway is that secondary glazing should be positioned against Part L and, for social and rented housing, against EPC and MEES targets, rather than against the Future Homes Standard directly. Where a client or planning authority raises the Future Homes Standard in connection with an existing building project, the accurate response is that it doesn’t apply to refurbishment work, and the relevant standard is Part L, applied with the heritage exemptions that typically govern listed and conservation area buildings.
Where a mixed-use development includes both new-build elements, subject to the Future Homes Standard, and refurbishment of an existing or listed structure, the secondary glazing specification applies only to the refurbishment element, specified against Part L rather than the new-build standard governing the rest of the site.
Frequently Asked Questions
Does the Future Homes Standard apply to secondary glazing? No. The Future Homes Standard governs new-build housing construction. Secondary glazing is a retrofit product for existing windows, so it falls under Building Regulations Part L rather than the Future Homes Standard.
Will the Future Homes Standard eventually apply to existing buildings? The Future Homes Standard itself is scoped to new construction. Existing buildings are governed by Part L, which has historically tightened in the same direction as new-build standards, though on a separate regulatory track and timeline.
Are listed buildings required to meet the Future Homes Standard? Listed buildings are not subject to the Future Homes Standard, which applies to new dwellings. Listed buildings undergoing refurbishment are typically exempt from the full force of Part L as well, reflecting the need to preserve historic fabric.
What regulation should I specify secondary glazing against if not the Future Homes Standard? Building Regulations Part L for thermal performance, Approved Document E for acoustic performance in relevant building types, and, for rented or social housing, Minimum Energy Efficiency Standards and the 2030 EPC targets.
Does secondary glazing help a mixed-use development meet the Future Homes Standard? Only indirectly, and only where the development includes refurbishment of an existing structure alongside new-build elements. The new-build portion must meet the Future Homes Standard through its own window specification, not through a secondary system.
Working on a refurbishment or mixed-use project and need to clarify which regulation your secondary glazing specification should target? Talk to our technical team or explore our secondary glazing systems and performance data.
