UK Energy Regulations
The latest technical amendments to the England AD-L2, Wales L2 and Section 6 Scotland Regulations for the conservation of fuel and power were published in 2023.From the 2013 revisions onwards, the Energy Conservation Regulations and Technical Handbooks have highlighted steps to take to achieve net zero energy buildings. The emphasis is on setting challenging on-site targets based on what levels of improvement would be most cost-effective over time. As before, the whole building is assessed using the SBEM ‘whole building methodology’ that expresses the energy performance. England and Wales both now use ‘Primary Energy’ as a key metric, whilst Scotland has introduced ‘Delivered Energy’.
MAJOR CHANGES
- Latest changes to Part L apply in England from 15 June 2022 (27% improvement over 2016 standards) and Wales from 29 March 2023 (28% improvement over 2014 standards).
- The updates to Section 6 Scotland came into effect from 1st February 2023, with an aggregated 20% improvement in CO2 emissions over the 2015 standards.
- Approved Document L2 for England and Wales now covers the requirements for both new build and existing non-domestic buildings in a single document.
- Carbon emissions have been retained, but Primary Energy is now an additional metric for compliance in England and Wales.
- ‘Delivered Energy’ has been introduced as a metric in Scotland
- Building Fabric Limiting Values have been tightened in all regions to align more closely with those of the ‘notional building’
- CIBSE TM23 is now the approved methodology for air permeability testing.
- Thermal bridging should be calculated at all junctions. Accredited details have been removed and penalties apply to default psi values.
IMPLICATIONS OF THE TARGET IMPROVEMENTS
In order to achieve the significant improvement in energy/carbon emissions savings, buildings will need to achieve:
- Lower fabric U-values
- Lower air permeability rate
- Improvements to lighting and controls
- Improved efficiency of services and controls
- Limitations on the effect of solar gain
Consideration will also need to be given to the inclusion of low carbon technologies for heating and hot water, along with photovoltaics, in readiness for nearly zero carbon buildings in the future.
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