The impact of Part L on construction

Part L Regulation Changes

The government announced in December 2021 that they would be adding several new regulations to Part L - which focuses on the conservation of fuel and power, which would come into force for all new dwellings, extensions, self-builds and renovations. The aim is to improve the current minimum standard for carbon emissions by 30%. 

There are essentially 4 documents which each focus on different aspects of construction;

Part L1A is for new homes

Part L1B is for extensions and renovations with some exceptions to the requirements

Part L2A is for commercial buildings

Par L2B is for 'other' buildings. 

New homes will now be assessed under the SAP10 calculation procedure (formally SAP 2012) and will set greater requirements for insulation. Part of the new regulations is around the audit of the installation. The builder is required to take photographs of the installation to confirm that design details have been followed and the photos of the insulation should have the geo-location information available to verify that the photos are of the correct plot. 

Dr Sarah Price, Technical Director at QODA Consulting (opens in new tab), says of these new recommendations: “The U-values are not going to have a big impact, but they do help a little towards reducing demand in new buildings. The photographic evidence has the potential to have a big impact on the actual performance of buildings – assuming it is checked by someone.”

U-values need to be improved in walls and replacement thermal elements from 0.28W/m2K to 0.18W/m2K, and the minimum values for doors, windows and roof windows have improved from 1.6 to 1.4. The U-value for doors has gone from 1.8 to 1.4, while fire doors can meet the U-value of 1.8 in line with previous standards. 

So when do these new regulations come into effect? 

Well, they already are. They became regulated on June 15th 2022. But a one-year grace period was granted for any construction in progress, so as long as the construction has been started before June 15th 2023, they are exempt from these new rules. But anything started after that date will need to comply. 

How Significant are the New Regulations?

On the surface, 30% may appear to be quite high but are far less than the Future Homes Standard of 75-80% 

Mark Siddall, principal architect and director of research at the Lovely Engineered Architectural Practice (LEAP), says: “I think the updates could go a lot further. We should be aspiring towards better-performing buildings, and the Building Regs are tailored towards the lowest common denominator. There could be more ambitious fabric standards and overall performance, which would cut people’s bills, improve their comfort and also reduce carbon emissions.” 

Where to begin

• Choose a local Energy Performance Certificate (EPC) assessor (find one here)
• Provide your assessor with the drawings and specifications in full detail
• Include Approved Construction Details (ACDs) as part of the design, if you can. These are large-scale section details of elements like window openings and eaves details. They aim to ensure airtightness and reduce cold bridging from key parts of the structure and help towards achieving compliance
• The designer agrees with SAP input or reviews it after advice if the design does not pass. Once the design has been amended and meets requirement L1A, the design assessment and SAP calculations are submitted to building control before work starts on site
• Construction begins; any changes from specification should be notified to the SAP assessor during the build to ensure it remains compliant
• Take detailed photos of all the required items and make sure it includes the Geo-location data to form part of the audit. If you are unable to do this, your assessor may be able to provide this as an additional service. 
• As completion approaches, an air pressure test is carried out and the photo report is given to the SAP assessor, including declarations of the ACDs used during the build
• Assessor produces the as-built SAP calculations and lodges an EPC against the new home’s postal address
• As-built SAP calculations and EPC are submitted to the building control body.

How Fonn can help

Fonn's app can capture photos of the build and automatically geo-tag them for the SAP assessment, the system can produce a full report in PDF format, capturing all of the relevant details, date and time stamps which will make the assessment much easier and provides full transparency to EPC assessor and end user. 

Fonn has been developing this feature with several well-known house-building companies to ensure that the platform is compliant and easy to use for the build team.

Our team have been implementing this solution with house builders to ensure they are ready as the June 2023 deadline approaches, and any company looking to do the same should start the process now.