Preparing for changes to ADL

The construction industry is facing a number of significant regulation changes over the coming years, with the consultation to approved Document L (ADL) 2020 closing on 10 January set to introduce significant sustainability challenges. James Hulbert of Knauf Insulation looks at how housebuilders should respond in a time of changing guidelines.

The ADL 2020 consultation proposes two options to uplift energy efficiency standards and requirements in preparation for the Future Homes Standard, which is planned to be fully implemented by 2025.

Option one requires a 20 per cent reduction in CO2 emissions compared to the current standard for an average home. It is suggested this will be achievable through fabric improvements alone, and effectively represents the Future Homes Standard fabric.

Option two, the Government’s preferred choice, requires a 31 per cent reduction in carbon emissions compared to the current standard. This will be achieved through carbon-saving technology such as photovoltaic panels, low and zero carbon technologies and better fabric standards, albeit not as high as in option one.

At first glance, Regulation 25B within the Consultation – ‘Where a building is erected, it must be a nearly zero-energy building’ – may seem alarming. However, both options in the consultation will meet the definition of ‘nearly zero-energy building.’

The consultation includes four key metrics:

  • Primary energy: incorporating the latest evidence on primary energy and CO2 emissions of fuels, and removing fuel factors in the calculation for highcarbon fossil fuels and electricity
  • CO2: the metric remains the same
  • Affordability: while electricity becomes ever greener, wholescale adoption now would result in higher energy bills for occupants
  • Minimum fabric standards: the fabric energy efficiency standard will be removed, instead the consultation lowers the limiting ‘backstop’ area weighted values for each element

So, between the close of the consultation and implementation of the changes to ADL in the second half of 2020, how can housebuilders prepare?

The first option is to do nothing and react at the point of implementation when software has been finalised and early ‘recipes to compliance’ are more fully formed. This doesn’t represent the most strategic policy however, and is likely to hinder land acquisition and planning in the interim.

A second option would be to leap headfirst and default to the proposed Appendix R reference values in SAP version 10.1 for the notional dwelling. Ahead of the final published version of SAP, this approach mitigates the risks of ‘wait and see,’ however it does potentially go well beyond the most cost-effective routes to compliance. It’s worth noting that the notional dwelling in the current iteration of ADL uses an external wall Uvalue of 0.18 W/m2K too, as does option two within the consultation document.

The third, most practical option, sits between these approaches. That is for housebuilders and developers to speak to their suppliers and manufacturers to understand how existing solutions can deliver cost-effective compliance in line with the proposed changes.

The efficacy of the building fabric remains in the front line, and it is critical that the changes implemented assist in one of the consultation’s additional aims – reducing the performance gap. Systems that are and can be delivered by approved technicians, monitored and traced therefore have an important role to play in achieving this goal.

One thing that is clear is that the transitional arrangements to ADL 2020 will be far shorter than previous documents, ensuring more occupiers benefit from the current energy efficiency standards sooner. Where construction has started, it is anticipated that regulations at that time will apply. Where work has not yet commenced, the 2020 regulations will apply regardless of when the planning/building notice was submitted. With different regulations likely to be applied on the same site, common construction details between ADL 2013 and 2020 offer the best route to smooth the transition and ensure quality.

Ultimately, by building effective partnerships with their supply chain, developers and housebuilders can update and evolve existing specifications to meet the new standards without redesign, helping to minimise additional costs. This means the houses built will perform closer to design values, achieve cost-effective compliance, and place the industry on a sustainable path to the Future Homes Standard too.

James Hulbert is head of housing at Knauf Insulation