Part L 2021 Overview

Part L 2021 Overview

What is Part L 2021?

Welcome to our Part L 2021 hub.

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.  High performance, energy efficient glass and windows are expected to play a crucial role in delivering nearly zero energy buildings (nZEB) in the UK.

The consultation process has started and it is important that our industry understands the opportunities these new requirements will bring.  Through its Future Homes Standard 2019 consultation ending on 7th February 2020 (extended from 10th January), the Government has set out its proposed changes to Part L (conservation of fuel and power) and Part F (ventilation) of the Building Regulations for new dwellings.
Consultation on proposed changes for existing dwellings and other buildings are anticipated in accordance with the following timeline:

Date Action 
 Late 2020 / early 2021 Consultations on:
  • Overheating in new dwellings
  • Energy efficiency standards for work carried out in existing dwellings 
  • Energy efficiency standards for new buildings other than dwellings 
  • Energy efficiency standards for work to existing buildings other than dwellings
 Early / mid 2021  Publication of new Part L, Part F and overheating regulations
 Mid / late 2021  Part L, Part F and overheating regulations come into force

Through our hub, we will monitor developments as the Part L 2021 consultation progresses and report on the implications as they emerge.

If you have any questions on Part L 2021 and what the implications might be for glass, please complete our online contact form, selecting 'Architect' or 'Trade' as the Nature of Enquiry and 'Part L' as the Enquiry Type.

Hand in hand with Part L are the compliance tools such as SAP and SBEM.  Although the tools contain default values for windows they do tend to be very conservative. We would encourage all designers to use manufacturers' values in these programs and real window sizes and orientations to realise the contribution that energy efficient windows can make.  Our Spectrum online calculator can be used to quickly determine the g value and centre pane U value for our range of thermal insulation and solar control glass.