Proof of compliance will be one of the major changes to Approved Document L in England next year, putting pressure on contractors to close the performance gap. But will this change be the silver bullet? Paul Barrett, Head of Product Management at ROCKWOOL, explores what the alterations to Part L mean for the specification and installation of insulation and whether the amendments need to go further.
From June next year, we will begin to see a series of changes to Approved Document L (ADL) as part of the shift to the government’s Future Homes Standard set to be introduced in 2025. Borne out of a need to close the gap between specified and as-built performance, one of the forthcoming amends will be greater scrutiny of build quality. In England, this will manifest itself as the introduction of a Part L (BREL) report, along with the need for photographic evidence of compliance.
This evidence will be provided to the building control body and the building owner to demonstrate compliance with energy efficiency requirements. Photographs will need to be taken at various construction stages before elements are concealed over to show build quality and that the designed details have been followed.
While photographic evidence is a good start, often performance gaps occur in areas that can’t be seen, thus we need a more stringent methodology to determine as-built performance. If we want to fully realise net-zero carbon by 2050 – as the Future Homes Standard hopes to in part achieve – specifiers and contractors must do more to ensure buildings perform well into the future and key to that is the effective specification and installation of a robust insulation solution.
Continuity for compliance
To reach the challenging carbon reductions set out in the Future Homes Standard, deliver designed performance and ensure low carbon heating systems can provide a comfortable indoor environment, continuity of insulation is critical. The first step in achieving this designed performance is to be certain that insulation is fitted contiguously and without gaps.
Stone wool insulation makes this process easier as it is highly pliable so can be closely friction fitted to frames, without the need for impractical levels of precision cutting. This simplicity minimises the margin for error, supporting reliable and effective thermal performance that reduces thermal bridging.
This process also applies to abutments between insulation boards, another area that can be prone to thermal leakage. The composition of stone wool insulation allows individual slabs to knit together to create a seamless fit and the workable nature of stone wool insulation supports the delivery of designed U-values.
While ADL 2022 is a step in the right direction, it does not go far enough in ensuring that buildings perform to design standard. Instead, specifiers and contractors should be raising the stakes, selecting durable insulation solutions that make robust installation easier and maintain performance longer term. By doing this, we can provide better performing homes for future generations and minimise our environmental impact.
For more information about stone wool insulation, and advice installing ROCKWOOL products, view the comprehensive range of installation guidelines: www.rockwool.com/uk/installation.