Beyond Part L: Why the housing industry must focus on more than just energy efficiency

The question of ‘real performance’ extends beyond energy efficiency, as regulations also look set to tighten in areas like safety and carbon reduction.
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When the updated Approved Document L (ADL) building regulations come into force in June, new homes will be required to produce 31% less operational carbon emissions and meet higher fabric efficiency standards. Housebuilders will also need to provide a new Building Regulations England Part L (BREL) report, including photographic evidence of thermal continuity and quality of insulation.

Understandably, this increased level of ‘as-built’ scrutiny is leading social housing providers to consider whether their stock performs as well in the real world, as it does on paper.

For example, all insulation materials have a thermal conductivity ‘lambda’ value. Theoretically, the lower the lambda value, the less heat is lost through the roof or wall. However, a low lambda value becomes meaningless if poor installation compromises the product’s performance.

Rigid boards for instance, can’t adapt to irregular surfaces, so if a wall’s inner leaf is not perfectly uniform and flat, they won’t sit flush against it. By contrast, the flexible structure of Mineral Wool insulation adapts to minor imperfections in the substrate, eliminating air gaps and maintaining thermal performance. As a result, Mineral Wool insulation is easier to install correctly, compared with other mainstream insulants.

We believe that closing the ‘performance gap’ between how buildings are designed and how they are built is the biggest challenge housebuilders will face, in complying with the new ADL requirements. But there’s a bigger picture for social housing providers to consider. The question of ‘real performance’ extends beyond energy efficiency, as regulations also look set to tighten in areas like safety and carbon reduction.

Ensuring safety

The fire safety of buildings has rightly moved into focus for both housing associations and the Government. The imminent Building Safety Bill 1 will introduce new requirements to ensure more products are safe and establish a New Homes Ombudsman Scheme, empowering homeowners to dispute sub-standard work.

Passive fire safety measures, like insulation, function as part of larger systems, within a building’s cavities, often involving third-party elements, such as fire breaks. As with thermal performance, deviation from the design specification can prevent these systems from living up to their fire-safety credentials. If this happens, the use of combustible materials creates a further level of risk, which is completely avoidable. That’s why non-combustibility is important.

Mineral Wool is non-combustible with the best Euroclass A1 and A2-s1,d0 reaction to fire classifications, so it will not contribute to the development or spread of fire, should it occur. It can also be used for a wide variety of applications, for example Knauf Insulation’s Supafil®, which is a Blown Glass Mineral Wool, DriTherm® Cavity Slab 32, a Cured Glass Mineral Wool that is water repellent and designed for use in external full-fill masonry cavity walls, and Cured Glass Mineral Wool Loft Rolls, which are often used for ‘cold roof’ installations.

Reducing carbon

Carbon reduction is another high priority for both Government and industry. The Future Homes Standard has established targets for 2025 and the Royal Institute of British Architects’ 2030 Climate Challenge has recommended that their own 2025 targets are adopted for new builds in design today.2

The need for products which reduce carbon emissions is equally front-of-mind for housing associations, with 74% already drawing up plans for how to make their homes ‘net zero’
by 2050.

But to reach net zero, we need to consider the carbon emissions generated by a building throughout its whole lifecycle, including through the products used and construction process – its embodied carbon. Glass Mineral Wool has the lowest embodied carbon of any mainstream insulation material, helping to reduce a home’s overall carbon footprint.

Whether the goal is ADL compliance, or getting ahead of future regulatory changes, Mineral Wool insulation is the reliable solution. With the added benefits of non-combustibility and acoustic performance, it’s the right choice for building homes that perform in the real world, as well as on paper.

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