Regulation 25a

Before work starts, you must carry out an analysis that considers the use of high-efficiency alternative energy systems in the buildings design. This is a requirement under Building Regulation 25A. You must give us notice that this has been undertaken.

Whilst it is a requirement for the analysis to be undertaken, this does not mean these systems have to be installed. The Target Emission Rates for the new building can be met in some other way.  There are no direct implications for the design, specification and construction of new buildings. Current standards and guidance applicable to heating and cooling systems are unchanged within the Part L Approved Documents.

The requirement for this notification is to encourage awareness, within the design process, of the benefits of such systems as part of new build development. High-efficiency alternative systems that may be considered include, but are not limited to:
  • decentralised energy supply systems based on energy from renewable sources
  • co-generation
  • district or block heating
  • heat pumps.

Complete a Regulation 25a analysis form (PDF, 7KB) and email building.control@iow.gov.uk.