Ask Pilkington


Ask Pilkington

What are the requirements for glazing for the next Part L?

Changes to Part L of the Building Regulations in England, including the supporting Approved Documents, are expected to have a significant impact on glass and glazing products in residential and non-residential buildings.  

The consultation process was undertaken in stages, beginning in late 2019 and ending on 13th April 2021. Through these consultations, the Government set out its proposed changes to Part L (conservation of fuel and power) and Part F (ventilation) of the Building Regulations for new and existing dwellings, as well as the introduction of a new regulation addressing the risk of overheating in new homes.

For new dwellings, for example, proposed changes to the minimum elemental standards for fabric performance – sometimes referred to as 'backstop' values - include reducing (improving) the window U value from 2.0 to 1.6 W/m2K. However, the expectation is that the U value will have to be much lower than this to enable new dwellings to achieve the whole building minimum energy performance target.

For replacement windows in existing dwellings, Window Energy Rating (WER) Band B or better, or window U value 1.4 W/m2K have been proposed.

A new regulation aimed at mitigating the effect of overheating in new dwellings could see a greater use of solar control glass, particularly in Greater London.

The expectation is that the new Part L, Part F and overheating regulations for England will be published in December 2021, coming into force in June 2022.

For more details about the proposed changes, visit our Part L 2021 hub by clicking here.

Was this helpful?
Thank you for your feedback.
We're sorry to hear that, please refine your search and try again.