KJ Tait

The need to implement Part L 2021 in Scotland

1 November 2022

The National Calculation Methodology (NCM) for Section 6 2022 is out for use from December this year.  This will reduce the carbon factor for grid electricity by circa 400%.  However, the document states that a further review of the EPC practice will be carried out during 2022/2023 in support of the Heat in Buildings Strategy and that the guidance for EPCs remains unchanged from Section 2015.

At KJ Tait, we have fundamental issues regarding the EPC methodologies under Section 6 2015 and the proposed Section 6 2022:

  • Section 6 2015: this does not incentivise the use of electricity as a heating source with buildings heated via gas and VRF being similar ratings.
  • Section 6 2022: due to the reduction in carbon emissions for grid electricity, every building would produce an EPC Rating of either A or B regardless of the installations.

Further to this, as the Section 6 EPC scale is directly attributed to carbon emissions there are certain buildings such as hotels and student residences that cannot achieve a better EPC than a ‘D’ rating.  This is caused by the assumed high hot water loads in these types of buildings under the NCM.


As a simple solution, we would like to see Scotland follow the new Part L 2021 methodology when carrying out EPCs.  This would negate the need for Section 63 assessments and would allow Scotland to bring in a minimum standard of EPC of ‘B’ by 2030, mimicking the current legislation in England that is accelerating real change.  Without this change, Scotland will continue to lag behind with decarbonising our existing commercial buildings and continue to create confusion across building owners.