Changes to U-Values Explained

The UK Government is considering some significant amendments to building regulations which will impact BWF Members and the wider woodworking and joinery manufacturing industry.

A consultation of the Future Homes Standard proposed a change to how U-values would be declared and if accepted, would replace the way they are currently declared in the Building Regulations Approved Document L (Conservation of fuel and power). Changes to Approved Document Q (Security in dwellings) are also under consideration.

The changes to both documents may require manufacturers of external doorsets and windows to adjust their testing, certification and compliance processes. We anticipate the new guidance for Approved Document L will be published in the summer but expect there to be a long transition period of at least a year. The proposals for Approved Document Q are yet to be consulted on and are therefore unlikely to be implemented in the near future.

What are the proposed changes?

Conservation of fuel and power: Approved Document L – Building regulation in England setting standards for the energy performance of new and existing buildings. Under the current requirements, a single U-value – calculated for a representative or ‘model’ product – is used across a range. The proposed new method would mean each individual external doorset and window supplied to new build projects will require its own U-value. If introduced, this method would incur significantly more costs as the number of calculations would increase considerably.

The new method would require joinery manufacturers to have access to a tool capable of calculating U-values for each product, taking into account variables such as size and configuration, glazing type and glazing bars, and timber species, timber-based materials and insulation materials used.

Security in dwellings: Approved Document Q – Building regulation in England covering security in dwellings. At present, Approved Document Q only applies to new builds. Under the proposed changes, all entrance doorsets and accessible windows would be required to meet an enhanced security standard, whether for new builds or existing buildings,

Should the changes to Approved Document Q be introduced, manufacturers will need to make sure their product ranges meet the enhanced security standards and can evidence their compliance with building control requirements.

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.