SAP Calculations for New Builds

Full SAP Calculations for new dwellings under Part L. Design Stage SAP, BREL report and PEA before you build; As-Built SAP and EPC at completion.

  • Required for every new dwelling
  • Design Stage SAP, BREL report and PEA
  • As-Built SAP and Energy Performance Certificate
  • Fixed prices, revisions included

Book Your SAP Calculation

Prefer to talk? Give us a call on 0333 567 9010 and we'll be happy to help.

  • Elmhurst Accredited
  • Fully Insured
  • 100s Projects Delivered
  • FHS Ready

Do I Need a SAP Calculation for My New Build?

Yes. Every new dwelling in the UK needs a SAP Calculation to demonstrate compliance with Part L of the Building Regulations. That covers self builds, developer plots, replacement dwellings and new flats.

Building Control need the SAP at two stages:

  1. A Design Stage SAP before construction starts, to show the design can meet Part L. This produces the BREL report and Predicted Energy Assessment.
  2. An As-Built SAP once the home is finished, using the final specification and air test result. This produces the Energy Performance Certificate (EPC).

Your design is measured against the Part L targets for Dwelling Emission Rate (DER), Primary Energy and Fabric Energy Efficiency (DFEE).

Each element also has to hit the building regs U-values for walls, roofs, floors and glazing, both the limiting caps and the lower notional targets.

SAP for Self Builders

If you are building your own home, SAP is one of the first things Building Control will ask for. The Design Stage SAP proves your plans meet Part L before you break ground.

Self builds often have more flexibility than developer homes. You can choose better insulation, an efficient heating system or renewables to hit the targets. We work with self builders to find the most cost-effective specification that passes without over-engineering, and we flag any issues early so there are no surprises at completion.

How to Pass New Build SAP Calculations

Part L 2021 is tougher than earlier versions, but most designs pass with sensible specifications. What usually makes the difference:

  • Good fabric: walls around 0.18, floors around 0.13 and roofs around 0.11 W/m²K
  • An efficient heat pump or boiler (gas needs better fabric to compensate)
  • Controlled ventilation such as MVHR, or dMEV in simpler homes
  • A little solar PV, often the cheapest way to close a gap
  • Revisions included until your design passes

The New Build SAP Process

  1. 1

    Design Stage

    We assess your plans, model the dwelling in SAP and produce the BREL report and PEA for Building Control.

  2. 2

    During Construction

    If the specification changes, we update the assessment. Add Project Support at booking for guidance throughout the build.

  3. 3

    As-Built and EPC

    Once the home is finished, we complete the As-Built SAP using the final specification and air test, then lodge your EPC.

What We Need for Your SAP

The more you can send upfront, the faster we can turn your SAP around. Most of it comes straight from your architect's drawings and specification:

  • Floor plans, elevations and sections with dimensions
  • Site plan showing orientation
  • Construction build-ups (walls, floor, roof) with insulation
  • Window and door schedule with U-values
  • Heating and hot water specification
  • Ventilation and any renewables (MVHR, solar PV, heat pump)

Don't have everything yet? We can work from reasonable assumptions and refine the SAP as your design develops. Our practical SAP checklist lists it all.

New Build SAP Pricing

Single plot pricing shown below. Book with a 50% deposit, and ask us about multi-plot discounts.

Small New Build <80m²

£275

Up to 80m² floor area.

Book Online

Medium New Build 81-150m²

£350

81 to 150m² floor area.

Book Online

Large New Build 151-250m²

£425

151 to 250m² floor area.

Book Online

Extra Large New Build >250m²

From £475

Over 250m² floor area. Call us for a quote.

Get a Quote

As a non-VAT-registered business, SAPgen does not charge VAT. All prices shown are the total payable.

What's Included

Every new build SAP includes:

  • Full SAP Design Stage calculation
  • U-value calculations for all elements
  • Thermal bridging and air permeability assessment
  • BREL report for Building Control
  • Predicted Energy Assessment (PEA)
  • Clear pass or fail result with recommendations
  • Revisions included until you pass
  • As-Built SAP and EPC available at completion

Frequently Asked Questions

Do all new builds need a SAP Calculation?
Yes. Every new dwelling in the UK needs a SAP Calculation for Part L. You need a Design Stage SAP before construction and an As-Built SAP at completion for the EPC and final sign-off.
What are the new build SAP requirements?
New builds must meet the Part L targets for Dwelling Emission Rate (DER) and Fabric Energy Efficiency (DFEE). The SAP checks your fabric U-values, heating, ventilation and renewables against these.
How long does a new build SAP take?
Most single dwellings are completed in a few working days once we have your drawings and specification. Larger developments take longer, and we'll confirm timescales when we see your plans.
What documents do you need?
Floor plans, elevations, sections, a site plan showing orientation, construction build-ups, a window schedule, and your heating and ventilation specification.
What happens if my new build fails SAP?
A fail on the first run is common. We give recommendations ranked by cost, usually better insulation, upgraded windows, or a little solar PV. Revisions are included until you pass.
Do you provide the As-Built SAP and EPC?
Yes. Once construction is complete we update the SAP with the final specification and air test result, then lodge the EPC. If we completed your Design SAP, the As-Built is at a reduced rate.
Will Building Control accept your reports?
Yes. All work is completed by an Elmhurst-accredited OCDEA using approved SAP software, and accepted by Building Control across the UK.

Ready to Get Your New Build SAP?

Fixed prices, revisions included. Book online or send your plans for a quote.