Part L 2021 Finalised

The Government released its new statutory requirements for energy, overheating and ventilation for buildings in England on the 15/12/21.  The following is an initial review of the updates which are largely the same as we have previously discussed in various articles:

• Regulations – The new tougher requirements covering energy, overheating and ventilation have been confirmed. These are presented in new Approved Documents (AD) which highlight the changes in law and the associated statutory guidance. The formally unspecified Approved Document [X] for overheating is now officially labelled as Approved Document (O).
• Timelines and application – The new requirements begin on 15^th June 2022. Building within any existing notices submitted before this date will have to start works before 15^th June 2023, else new regulations will apply. Compliance will therefore be by building and not by development. Developments with staggered building starts after the transition period will require different strategies.
• Energy requirements (AD L) – There are 3 compliance requirements written into the law covering fabric energy efficiency, primary energy efficiency and carbon emissions. The fabric energy efficiency target requires a at least a 15% improvement over the current target (see article). The carbon emission target uses new lower emission factors so quick wins such as PV will have less of a benefit.
• Heat networks – The approved documents stipulate minimum carbon emission and primary energy performance requirements for new and existing district heat networks. Achieving these performance metrics does not guaranty compliance with AD L. We await the release of the accompanying SAP Manual to be able to understand fully how heat networks will perform. The parameters do require limiting heat losses and careful heat generating plant selection. The values suggest that heat pump use on district heat networks will be favoured in place of CHP or gas boilers.
• Overheating (AD O) – There is a legal requirement to ensure reasonable provision has been made to prevent overheating. The biggest change from the consultation proposal is to allow the use of mechanical cooling, after all other measures have been utilised. There are still two compliance routes, with dynamic modelling utilising an adapted version of TM59 providing the most design flexibility.
• Non-domestic – Achieving compliance for non-domestic units continues to get tougher. There are also calls for more complex additional assessment to predict energy use for units greater than 1,000 m²
• Comparison to the London Plan – The London Plan put us on notice that it will change its requirement on release of the new regulations. The requirements are however uncertain but could impact schemes going through the planning process.

There is a significant level of detail still to be reviewed and we will be following this article up with relevant and important information in the new year.