The construction industry has just a few more weeks in which to respond to the government’s proposed revisions to Parts L and F of the Building Regulations – the first step towards its Future Homes Standard.

And insulation specialist Actis has been working with the Structural Timber Association on the organisations’ responses to the proposals, which, once amended, are expected to come into effect in the latter half of 2020.

The revised regulations will act as a stepping stone towards the far more stringent energy efficiency requirements for new homes to be laid down under the forthcoming Future Homes Standard, which should be in place by 2025.

That in turn will play a key role in enabling the UK to meet its 2050 net zero target.

The 98-page MHCLG (Ministry for Housing, Communities and Local Government) Part L and Part F consultation document asks for feedback from individuals and companies working in the construction industry on a range of proposals covering energy performance, air tightness, ventilation and relevant routes to compliance.

It also looks at transitional arrangements to ensure builders can’t evade revised rulings by obtaining planning permission before changes are implemented and building to retrospective standards too long afterwards.

A key section of the document sets out two alternatives for a reduced Target Emission Rate – a choice of a 20 per cent or 31 per cent CO2 reduction.

While Actis’ UK and Ireland technical director Thomas Wiedmer and his colleagues, understandably, support the more stringent option they are suggesting greater focus on the principle of fabric first and recommending that the government-proposed U-values for walls be improved from a target of 0.26 to 0.22 or 0.21 W/m2K.

The government document suggests the lighter option, supported by the STA, could be delivered via very high fabric standards, while its more hard core alternative would have slightly less stringent fabric requirements and the addition of technology such as solar pv panels.

This scenario would add an estimated average of £4, 847 to the build costs and save the householder £257 per year on heating bills.

That would give the industry five years to wean itself  towards the government’s 2025 aim of reducing CO2 emissions from new homes by 75 to 80 per cent compared with current levels.

Thomas explained: “We and the STA are of the opinion that energy efficiency standards should always be based on reducing the need for energy first and in particular limiting the heat loss through thermal elements  – that is through achieving excellent U-values, reducing thermal bridging and improving airtightness – the fabric first principle.

“Reducing the heating energy demand through a fabric first approach is the only practical way to achieve net zero carbon homes in reality.”

Actis and the STA are also supporting the MHCLG’s call to include build quality guidance into the revised Part L regulations to help builders eliminate the performance gap and reduce thermal bridging – two issues on which Actis is very proactive.

The deadline for responses to the consultation document is February 7th 2020.