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Latest Changes to Part L Building Regulations

22nd March 2022

Changes Part L Building Regulations

Do you know about the latest changes to Part L Building Regulations?

The changes are part of the Governments step towards their target to deliver Zero Carbon Ready Homes by 2025.

From 15th June 2022, all new homes must produce 31% less CO2 emissions than what is currently acceptable in the present Part L regulations. Therefore, the construction of new dwellings must comply with the increased energy performance standards as set in the new regulations.

An on-site audit will be required to confirm that the designed details have been constructed, and photographs must be taken as evidence to form the BREL report.

What is Thermal Bridging? Why is it a concern for CO2 emissions?

A “thermal bridge” (also known as a “cold bridge”) is a disruption in a building’s thermal wrapping, such as a gap in insulation. Thermal bridging causes heat loss and condensation. Heat loss has a significant impact on the energy efficiency of a building, making this a crucial problem to target to reduce CO2 emissions.

How can Thermal Bridging be reduced?

Insulation must be continuous. This applies to areas such as walls, roofs, windows & doors, and the junctions between these areas. For example: Roof insulation should be continuous with wall insulation. The regulations advise that “opportunities should be considered to use products that help to reduce thermal bridges”.

How can ARC help?

An area that can be the hardest to fully insulate is the ‘triangular cavity’ in the eaves. Traditionally, mineral fibre product is manually applied over the ceiling trusses and forced through the narrow gap at the wall plate and ceiling junction. The triangular area can be problematic for housebuilders to consistently insulate on-site: the amount of mineral fibre required can be difficult to calculate, and access to the all-important areas virtually impossible to achieve.

The ARC Eaves Insulator has been specifically shaped for the ‘triangular cavity’, manufactured to suit the loft depth and the roof pitch. Installed before the roof is complete, ensuring all the required areas can be accessed, the ‘stalk’ of insulation is placed into the top of the external wall cavity, with care being necessary to ensure a snug fit. The circular overlap of the insulation is pushed in between the roof trusses to rest at ceiling level – this fills the ‘triangular cavity’.

ARC Eaves Insulator - Reduce Thermal Bridging

The on-site audits and evidential photographs that will be recorded will include the inspection of the eaves. The advantage of using the Eaves Insulator is that it will be easier to evidence that the eaves area is filled with insulation, versus the traditional method of insulating the eaves which is likely to have inconsistencies, gaps or incorrect thickness.

The product can help to improve your SAP calculation – ARC Eaves Insulator reduces heat loss through the wall plate junction by up to 49% compared with traditional loft insulation (varies by detail – see datasheet for more info)

For more information about the ARC Eaves Insulator, and to view the technical datasheet, please visit the product page.

When do the changes affect me? 

Transitional agreements are in place – if a building notice, initial notice, or full plans for building work are submitted to a local authority before 15 June 2022, then provided the building work commences by 15 June 2023, work on that individual building is permitted to continue under the previous standards. The Approved Document L, Conservation of fuel and power, Volume 1: Dwellings is for use in England. Compliance will differ to standards required in Scotland, Wales and Northern Ireland. Read the full published document here.