Welsh Building Regulations Part L Update

Following the successful update to Part L building regulations in England this year, today marks the launch of the updates to Part L in Wales. The key changes introduced within the Welsh Part L 2021 update for dwellings are summarised below:

  • A 37% reduction in CO2 emissions over Part L 2013 has been introduced.
    • Please note that the English Part L 2021 update requires a lower 31% reduction in CO2 emissions over Part L 2013
  • A new metric of Primary Energy Compliance is present, which accounts for the whole life emissions associated with a unit of energy across all stages such as extraction, refinement, transportation, consumption etc.
  • A new minimum energy efficiency standard has arisen as a result of the ‘Householder Affordability’ scheme, which sets a minimum EPC rating of 81 (B) for new builds in an effort to tackle fuel poverty.
  • Achieving all limiting fabric standards is now mandatory, and the standards have been tightened over Part L 2014.
  • 100% air testing on site must now be conducted, as opposed to the prior option of conducting average air testing based on house type.
  • Overheating risk has been separated into Approved Document Part O, and is no longer included within SAP or Part L.
  • The SAP10 methodology has been adopted to calculate the energy performance of domestic buildings.
  • Photographic evidence must be provided to evidence the as built checks, such as insulation and ventilation and heating systems.
  • Regulation 25A, High Efficiency Alternative Systems report, has been simplified.  Developers must still investigate the viability of low carbon and renewable systems for the site, but are no longer required to give notice to the local authority (unless requested).  This arose due to the expectation that a greater number of dwellings will require renewables to comply with SAP10, mitigating the need to prove that renewables have been considered.
  • Transitional arrangements are now considered on a plot-by-plot basis, allowing a period of one year to commence significant construction in order to be assessed against the building regulations that were applied to.

This update signals an extremely positive change for energy efficient design in new build developments, but comes with a significant impact on both build cost and design considerations.

The Element Sustainability team includes qualified and experienced energy assessors who would be pleased to answer any queries you may have about these new and exciting changes coming into effect in Wales. If you would like to discuss the implications for your project, please get in touch!

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