The FHS is a keystone of the government’s emissions reductions strategy. The wider target is for the UK to be a net-zero carbon economy by 2050 and currently construction and buildings in use account for around 25% of the country’s carbon emissions. That picture clearly must change and the FHS is drafted to do just that.

The FHS – Cutting housing emissions by 75%

The FHS sets out the way new homes are to be built, heated and ventilated to cut their emissions by at least 75% against those constructed to previous regulations. It means an industry-wide switch to renewable heating technologies and, in conjunction, improvements in building envelope performance to cut energy wastage. Homes will as a result be ‘net-zero ready’. That means they will become net-zero without further retrofitting as the electricity grid fully decarbonises.

“We need the Future Homes Standard to meet our Net Zero targets and to ensure we provide future generations with homes that are efficient, cost-effective and healthy,” said Catherine Adams, Director Net Zero at the Department for Levelling Up. “It is likely to be the biggest jump in energy efficiency standards of new homes in a generation.”

Part L changes are core to the FHS

After consultation, the final form of the FHS was unveiled in March 2026. The new rules come into force in March 2027. From then to March 2028 there will be a limited transition, with some projects allowed to be delivered under previous regulations depending on the dates plans were submitted and construction commenced. From March 2028 all new projects must comply in full.

At the core of the FHS are major changes in Building Regulations Part L on energy performance. Previously the primary focus was on reducing energy use. The remit of Part L 2026 is broadened to address greenhouse gas emissions more holistically. It stipulates that heating and hot water must be delivered by electricity, with low-carbon systems, including heat pumps, communal heat networks and photo-voltaic (PV) panels integrated from the start of design.

Gas boilers will no longer be allowed in homes and there is a much larger requirement for PVs. Most new homes will require panel arrays sized to around 40% of ground floor area.

New levels of airtightness required by the FHS

Under the last revision of Part L in 2021, the airtightness of a notional dwelling was tightened to 5 m³/(h·m²) at 50 Pa. The FHS takes that to 4 m³/(h·m²). That compares to a typical new-build homes currently achieving 4–6 m³/(h·m²) so means a step change, with airtightness testers becoming an essential part of every new build.

New airtightness rules are accompanied in the FHS by changes to Part F on ventilation which address the type of technology and installer competence. In conjunction, a technical review is being undertaken of Building Regulations Part O, introduced in 2022, to reduce risk of homes overheating.

Build fabric considerations are critical to the FHS and timber frame construction

Earlier consultations on FHS led to calls for stricter home fabric standards, but the Government has decided these should remain ‘broadly aligned’ with those of Part L 2021. However, compliance will rely on good insulation, airtight construction and detailing that minimises heat loss at junctions.

A new Standard Assessment Procedure, SAP 10.3, has been developed to demonstrate compliance. This will be superseded by the Home Energy Model, a new calculation methodology expected to be ready shortly.

Timber frame construction is a valid route to compliance

The FHS puts significant demands for improvement on all construction methods, regardless of building materials. However, the timber-frame and broader timber-based building sector believes it is particularly well placed to meet the standard given timber buildings’ inherent strengths in terms of insulation and airtightness. Moreover, the industry continues to make advances in levels of timber-based housing’s lifetime energy performance. It’s doing this through its construction approaches and introduction of innovative new technologies.

One reason timber frame is seen as having the edge in ensuring FHS compliance is that timber itself is an inherent insulant. This, say suppliers and manufacturers, helps regulate internal temperatures, reducing energy consumption for heating and cooling.

Timber frame construction is also less prone to thermal bridging than masonry or steel-framed buildings. It typically has deeper wall cavities too, accommodating more insulation. The overall result, say suppliers, is U-values of timber frame systems down to 0.14 W/m2K and lower.

Timber frame construction can offer component precision

Particularly high levels of precision prefabrication of timber frame components additionally enhance airtightness. And this is taken to even higher levels in offsite construction where whole building assemblies are fabricated in quality- and climate-controlled factories for rapid construction on site. Timber is increasingly widely regarded as the prime material for offsite manufacture given its strength to weight and ease of processing. Recognising its merits, a significant proportion of leading UK housebuilders now have their own timber frame factories.

Modern timber frame design is also billed as delivering greater flexibility when it comes to incorporating renewable energy technologies, including PV panels, heat pumps and mechanical ventilation. Associated ducting and services are easier to accommodate, say timber frame suppliers.

Weather-resistant barriers can perform key roles in timber frame construction

A key component in timber frame construction, including for helping to achieve required energy performance levels, is the weather resistant barrier (WRB). These protect timber components and assemblies from the elements on site, preventing water ingress and minimising potential later problems with timber movement, mould or decay.

There is a range of established weather resistant barrier types. The most widely seen in the UK is probably the site-fixed polypropylene or polyethylene house wrap. An older technology is building paper, which is asphalt-impregnated kraft paper. Then there are other more modern self-adhered peel and stick membrane solutions and fluid-applied products.

These all perform an effective protective function, and, additionally, bar building paper, are vapour-permeable allowing any moisture in the building envelope to escape. They also support building airtightness.

Thermally fused integrated weather resistant barriers

Thermally fused integrated weather resistant barriers are applied by panel producers in their factories under heat and pressure in a minimal-waste process. This means consistently uniform coverage, leaving no gaps for water ingress. Processed panels are delivered to site ready-protected and equally can be incorporated into timber frame assemblies in offsite factories.

Arctek® Dryshell™ supports timber frame build efficiency

Arctek® Dryshell™ is one such thermally fused integrated weather-resistant barrier. It is a solution that deskills the timber frame weather protection process and joints between Arctek® Dryshell™ coated panels are simply and easily taped.

Ultimately, Arctek® Dryshell™ is designed to help the timber frame industry efficiently deliver quality, high-performance, low-carbon homes. In fact, the sort of homes the FHS requires UK construction to build.

To find out more about how Arctek® Dryshell™ can support your future timber building projects, request a sample or enquire here.