Rob Adkins, Director, shares the following notes on the 2021 Building Regulations, which we hope will be of interest to you:

The Building Regulations 2021 Approved Document L1A (Conservation of Fuel and Power in New Dwellings)

The new Part L is due

to be published in December 2021 with an implementation date of June 2022.

This means developers must submit their Building Notices, Initial Notices or deposit their Full Plans application by June 2022 to remain under the 2010 Regulations. In order to do this, a “meaningful start” needs to have been made on the site before May 2023. The meaningful start date relates to each individual house and not site wide… For example, if you have a project for the creation of 20 dwellings and make a meaningful start on plots 1-10 before May 2023, these will remain under 2010 Regulations. If the remaining plots (e.g. 11-20) have not been meaningfully started before May 2023, the new (2021) Regulations will need to be adopted for those ten dwellings.

The outline implications of the 2021 Regulations are:

  • Dwellings will need to pass SAP 10.3
  • Heating to be via Heat Pump or some type of electric system. (Gas boilers will pass SAP, but with an increase in the amount of work required in order to attain this)
  • Thermal bridging has been removed – manufacturers tested data or default Y values will have to be used
  • Showers will need to be limited to 8L/min flow
  • Overheating will now be assessed under the new Overheating Regulations, which will restrict window opening sizes
  • Thermal elements (0.18 External Walls / 0.13 Floor / 0.11 Roof / 1.2 Windows / 0.05 Default Y value / Air Permeability of no less than 5 but no more than 8)
  • All internal lights need to be efficient (80Lm/w minimum)
  • Requirement for hot water recovery to the showers
  • PV requirements have been set based 40% of the dwelling floor area (e.g. 100m² house =  6.15kWp system or 20No. 100m² apartments over five floors = 1.25kWp per apartment).
  • All properties need to be pressure tested individually
  • Ventilation systems 1 & 3, using an air pressure test less than 3 has no benefit, if you have a desire to test less than 3, you need to adopt system 4 ventilation
  • A BREL compliance Report will be required for every property built signed by the SAP assessor and Contractor and containing information including details of construction, wall make-up, insulation, schedule of thermal bridging, photographic evidence of the build etc.


In summary: 

2021 December – Documents Released

2022 June – Enforced

2023 May – Start on site needs to have commenced to retain 2010 regulations, otherwise 2021 Regulations to be adopted.


It is further anticipated that the next set of regulations to be released in 2025 (entitled Future Homes) will suggest:

  • Windows must be triple glazed 0.8 and be BFRC approved & certified
  • Wall 0.15
  • Gas will be banned
  • Heating via Heat Pump (allowing the removal of PV and shower heat recovery)
  • No benefit from using ground source compared to air source heat pump

The Government has based the new 2025 regulations on the grid being more “green”, therefore the need for PV and waste recovery has been reduced. However if the grid has not achieved these green targets, we will see further changes to the proposals.

If you would like to discuss the how the forthcoming regulations may affect your projects, please do call us on 0121 214 8998 and we will be only too delighted to assist.