What Software is Used For SAP Calculations in 2026

To work out results of your SAP Calculation, there are multiple different software packages that SAP Assessors use. Below we’ll cover the three main applications and learn why SAP Calculations cost what they do.

What is SAP Software?

SAP Software is the program that energy assessors use to confirm that a new dwelling meets the building regulations set out in Part L1A (conservation of fuel and power).

First, lets cover a common query. To be able to produce a compliant SAP Calculation, it’s more than just a software package. It needs to be completed by a trained and accredited assessor. You can’t just download software and produce your own BREL report.

An On Construction Domestic Energy Assessor (OCDEA) – this is us – use SAP software in conjunction with the SAP methodology, currently SAP 10.2, to create Part L compliant SAP Calculations. We’ve been trained how to use the conventions in the BRE SAP methodology to current standards.

Most, if not all SAP Software is gated for use by qualified and accredited OCDEAs.

The Main SAP Software Options

Each assessor usually has a preference on software the use to produce SAP calculations. This could be the software they were trained on, interface preferences or licencing costs. Lets have a look at the two most popular packages in use by active OCDEAs.

Design SAP 10 by Elmhurst

Elmhurst are the largest accreditation body in the UK. Around 50% of all EPC lodgements happen through Elmhurst. Their own Design SAP 10 software is the natural choice for their accredited assessors. It costs around £360 a year and is completely web based meaning assessors can pick up on any job from any site.

JPA Technical

This is the preferred package of members of the Quidos accreditation scheme. Again this is a web based product with an upfront cost of around £500 and a year two onwards renewal fee of £170 or so.

Both of these packages are government approved for producing Design SAP Calculations, As Built SAP Calculations and EPCs.

The SAP Calculation Process

When an assessor receives your project, they input building details into SAP software which runs
a complex thermal model. The software calculates monthly energy use by working out heat demand,
solar gains, and internal heat sources for each month of the year.

The assessor enters construction details including U-values, heating system and ventilation spec. The software then models how much energy your building will use and produces three key metrics: carbon emissions (DER), primary energy use (DPER), and fabric efficiency (DFEE). All three must pass their targets for Building Regulations compliance.

Where human expertise matters is interpreting your plans correctly and choosing appropriate assumptions when details are missing. An experienced assessor knows which boiler database entry matches your actual system, how to handle thermal bridges, and what to do when initial calculations fail. We can suggest targeted improvements that achieve compliance cost-effectively rather than over specifying everything.

The software is precise, but garbage in means garbage out.

Can You Do SAP Yourself?

No.

A compliant SAP Calculation leading to a Building Regulations England (or Wales) Part L (BREL/BRWL) report needs to be produced by a qualified, accredited SAP Assessor.

There are a few free online calculators and estimators, but these are not SAP Calculations and cannot be used for compliance.

The Future of SAP Software

We’re on the cusp of a huge change in the industry. SAP is being replaced by the Home Energy Model (HEM). We’re expecting release in late 2026 or early 2027 and after a short transition period, SAP Calculations will be replaced with HEM Calculations. At that point, there will be an updated suite of compliance software.