Energy services

There's always a requirement to meet the minimum efficiency standards for compliance with the building regulations, whether the work is for a new build, a conversion, or an extension to an existing dwelling. Approved Document L (Volume 1) of the building regulations (Conservation of Fuel and Power) sets out these minimum requirements to achieve compliance. 

As the UK transitions towards net zero, these minimum requirements are ever increasing, and it's important that all properties, whether existing or new build, meet the minimum requirements.

The latest standard is Approved Document L 2021 (England). The currently SAP methodology is SAP 10.2. 

Our Energy Services Team keep up to date with the latest updates to changes in regulations concerning domestic properties, and are able to provide the following services...

New build (SAP/BREL/EPC, water and overheating)

All new-build dwellings require a SAP (standard assessment procedure) assessment with BREL report (Building Regulations England part L) (or BRWL for Wales – Building Regulations Wales part L). 

This is provided at the 'as designed' stage, and at the 'as built' stage along with the EPC. A compliant SAP/ BREL (or BRWL) demonstrates compliance with approved document L.   

Water calculations are also required to demonstrate compliance with approved document G (water efficiency).  

With the introduction of the latest regulations, all newly built properties also require an overheating calculation, which demonstrates compliance with approved document O (overheating). 

Our service includes:

  • As designed/as built EPC, including relevant U-value calculations and thermal bridging details 
  • Water calculations to demonstrate compliance with approved document G 
  • Overheating calculations – using the simplified method – to demonstrate compliance with approved document O. Note, we don't currently offer the thermal dynamic method.

Conversion (SAP/BREL/EPC and water)  

All conversions where a new unit of accommodation is being created also require a SAP at the 'as designed' and 'as built' stage, along with an EPC. A compliant SAP demonstrates compliance with approved document L.    

Water calculations are also required to demonstrate compliance with approved document G (water efficiency). 

Overheating calculations aren't required for conversions.  

Our service includes: 

  • As designed/as built EPC, including relevant U-value calculations 
  • Water calculations to demonstrate compliance with approved document G 

Extension (excessive glazing calculations)

Extensions to existing properties which are excessively glazed (glazing over 25% of the floor area), may also require an excessive glazing calculation. Compliance is demonstrated by one of two methods: 

  • Area weighted U-value 
  • Whole house SAP comparison 

Our service includes a calculation to demonstrate compliance using one of the above methods, with full U-value calculations. 

Current framework 

The 2021 regulation changes included the following: 

Changes to parts F (ventilation) and L (conservation of fuel and power), the introduction of overheating with approved document O, and provision for electric car charging with approved document S. 

The new SAP 10.2 framework is now used to demonstrate compliance with approved document L. It places greater emphasis on fabric efficiency, renewable technologies, zero-carbon heating, thermal bridging and more besides. 

Photographic evidence is now a requirement, and it's not possible to issue a compliant BREL report without the required photographic evidence. 

Part O was introduced to address the issues associated with well-insulated housing overheating in the summer. This looks at the amount of glazing based on the elevation, and the number of windows/doors that can open to remove excess heat. 

Useful links on current requirements concerning energy

Approved documents

The future

The government’s Future Homes Standard will apply to new homes in England, likely towards the end of 2026. It’s designed to make homes warmer, greener, and cheaper to run.

What’s changing?

  • Elimination of fossil fueled heating – homes will use low-carbon heating, such as heat pumps or heat networks. Cost metrics which currently disadvantage low-carbon heating are likely to be adjusted
  • Fabric first – the high levels of insulation set with the previous update aren't expected to significantly change (however, this remains to be determined)
  • Solar panels – most new homes will require solar PV panels
  • Future-proof design – homes will be ready for a zero-carbon future without costly retrofits.
  • Replacement of the Standard Assessment Procedure (SAP) with the Home Energy Model (HEM) and new EPC metrics (it's expected that SAP and HEM will work alongside one another for a certain period). HEM is designed to better reflect energy costs/ efficiency.

FAQs

When does it start?

Likely late 2026, with a transition period as was the case with the previous update. It is however worth noting that the government has delayed a response to the consultation until early 2026, so this date may change.

Will it affect existing homes?

No, it will only apply to new homes built after the implementation of the new regulations.

Why is it important?

It helps to tackle climate change, lowers energy bills, and ensures homes are ready for a zero-carbon future.

Useful links

Make an energy application/enquiry

Email our energy surveyors and they'll be happy to help.