SAP Calculations and EPCs for New Homes

SAP Calculations and EPCs for New Homes

A SAP calculation shows that a new home meets Part L of the Building Regulations, and it produces the home's EPC. Every new dwelling in England needs one, and so do most conversions and some extensions. We take your project from design stage through to the final certificate.

When you need one

• New-build houses and flats
• Conversions and changes of use that create a home, such as offices or barns
• Extensions where the glazing is more than 25% of the extension's floor area
• Planning applications that ask for predicted energy ratings

What you get at each stage

• Design stage. Before work starts: the design SAP, the Part L compliance report for building control, and a Predicted Energy Assessment you can use to market the homes off plan.
• During the build. If the design or specification changes, we rerun the calculation and tell you what it does to the result.
• As built. Once the air test is done, we update the SAP with what was actually installed, issue the as-built compliance report and lodge the EPC.

What the calculation checks

Under Part L 2021 a new home has to beat three targets: carbon emissions, primary energy and fabric energy efficiency. It also has to meet minimum standards for insulation, heating and airtightness. If the first run does not pass, we tell you which changes will get it through at the lowest cost.

The Future Homes Standard

The Future Homes Standard was published on 24 March 2026 and comes into force on 24 March 2027. New homes will need low-carbon heating, in most cases a heat pump, and solar panels.

A home can still be built to the 2021 rules if the building notice or full plans were submitted before 24 March 2027 and work on that home starts before 24 March 2028. The rule applies to each home, not to the whole site. Send us your dates and we will confirm which standard applies.

What we need from you

• Floor plans, elevations and sections
• A site plan showing orientation
• Construction details for walls, floors, roofs and windows
• Heating, hot water and ventilation specification
• Any planning conditions on energy

Price and turnaround

From £100+VAT per home, including U-value calculations and the EPC. Schemes with several homes are priced per project.

Turnaround: 3 working days once we have your drawings and specification.

Questions we get asked

What is the difference between a Predicted Energy Assessment and an EPC?
The Predicted Energy Assessment comes from the design-stage SAP and is used to market a home before it is finished. The EPC is the final certificate, lodged once the home is built, and it lasts 10 years.

What evidence do you need at the end?
The air test certificate, photographs of insulation and junctions taken during the build, commissioning certificates for heating and ventilation, MCS certificates for any renewables, and confirmation of what was installed.

My design does not pass. What now?
We model the options, such as better windows, more insulation, solar panels or a different heating system, and tell you which one costs least.

Do you also do the overheating and water calculations?
Yes. Most new homes need Part O and Part G as well, and we work from the same drawings.

Send us your drawings by email or WhatsApp and we will come back with a quote and a turnaround time.

Overheating: Part O and TM59

Most new homes also need a Part O overheating assessment. We do the simplified method and, where the design needs it, TM59 dynamic modelling, from the same drawings as the SAP.

Part O overheating assessments
TM59 dynamic overheating assessments