How proposed building regulation changes could impact external doorset & window manufacturers

The UK Government is considering changes to Approved Document L and Approved Document Q, which could significantly impact manufacturers of external doorsets and windows. Proposed updates to Document L would alter how U-values are declared, while potential amendments to Document Q could introduce stricter security standards. These changes may require manufacturers to adjust their testing, certification, and compliance processes. In this blog BWF Technical Director, Kevin Underwood provides a summary of the key proposals, expected timelines, and what joinery manufacturers need to prepare for in the coming months.

Changes to Approved Documents L (Conservation of Fuel and Power) and Q (Security – Dwellings)

Manufacturers of external doorsets and windows should be aware of two potential changes to England’s building regulations that could significantly impact their products.

The first concerns Approved Document L, where last year’s Future Homes Standard consultation proposed a change in how U-values are declared for external joinery. The second relates to a potential amendment to Approved Document Q, which could introduce a requirement for all entrance doorsets and accessible windows to meet enhanced security standards.

Approved Document L – U-Value Changes

The consultation on the Future Homes Standard (which ran from 13 December 2023 to 27 March 2024) proposed that U-values be declared for each individual external doorset and window supplied to new-build projects. This would replace the current method, where a single U-value—calculated for a representative or ‘model’ product—is used across a range.

Joinery manufacturers will need access to a tool capable of calculating U-values for each product, factoring in variables such as:

• Size and configuration (e.g., opening vs. fixed lights)
• Glazing type and glazing bars (e.g., traditional vs. simulated, single vs. multiple bars)
• Timber species, timber-based materials, and insulation materials used

Approved Document Q – Security Requirements

The proposed changes—yet to undergo consultation—would require all entrance doorsets and accessible windows, whether for new builds or existing buildings, to meet an enhanced security standard, such as PAS 24:2022+A1:2024. Currently, Approved Document Q applies only to new-build dwellings.

Manufacturers will need to ensure their product ranges are covered by enhanced security testing or have access to third-party test evidence (e.g., from a hardware supplier) that meets building control requirements.

Implementation Timeline

In January, the Future Homes Hub provided insights into the timing of the Future Homes Standard and changes to Approved Document L:

• The Home Energy Model (HEM), which replaces SAP, is expected to be available by May 2025.
• The government aims to publish the new standard as soon as possible—likely in summer 2025 (June/July).
• The final regulations will require around five months for government processing before publication.

The changes to Approved Document Q are yet to be consulted on and so any changes are unlikely to affect joinery manufacturers any time soon. The BWF has contributed to the development of a revised Approved Document Q but it won’t be until a consultation draft is released by the Home Office, or The Ministry for Communities and Local Government (MHCLG) if security follows the lead of fire safety and moves department.

Next Steps for Joinery Manufacturers

The BWF will continue to work with the government and industry trade associations to keep members informed of regulatory changes. It will also support manufacturers with guidance on meeting new requirements as they come into effect.