Elmhurst Accredited SAP Assessor

SAP Calculations for New Builds, Extensions & Conversions

Name: SAPgen
Address: 4 Grange Avenue, Warrington, Cheshire, WA4 1PN, GB
Telephone: 0333 567 9010
Price range: ££

Fixed price SAP Calculations for Part L compliance. Fast turnaround. Reports accepted by Building Control nationwide.

New builds, conversions and extensions
Design SAP, As-Built SAP and EPC
Results typically in 2 to 4 working days
Practical advice if your design does not pass first time

Work directly with a qualified SAP assessor, not a call centre.

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Elmhurst Accredited PI Insured 2-4 Day Turnaround Fixed Pricing

SAP Calculations Explained

The essentials before you get a quote.

What is a SAP Calculation?

The Standard Assessment Procedure (SAP) is the government's method for measuring the energy performance of a new dwelling. It produces the figures Building Control need to confirm your project meets Part L of the Building Regulations, plus the EPC.

Who needs one?

Anyone building a new home, converting a building into a dwelling, or adding a larger or heavily-glazed extension. Builders, architects, developers and self-builders all need one to get Building Control sign-off.

Why do you need one?

It is a legal requirement for Part L compliance. Without a passing SAP Calculation and the resulting EPC, Building Control will not sign off the work. A Design stage SAP also flags issues early, while they are cheap to fix.

Where do you work?

Everywhere in the UK. SAP Calculations are produced from your drawings and specification, so we support projects wherever you are building.

How much does a SAP Calculation cost?

Part L Compliance

from £95

Reference method & U-value checks for extensions

Full SAP Calculations

from £275

New builds, conversions & whole-house projects

Fixed prices with no hidden fees. Multi-plot developments benefit from lower per-plot pricing.

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What Is a SAP Calculation, and When Do You Need One?

A SAP (Standard Assessment Procedure) Calculation is the government's approved method for measuring the energy and carbon performance of a home. It models the fabric, heating, hot water, ventilation and any renewables to confirm the dwelling meets Part L of the Building Regulations, and it produces the Energy Performance Certificate (EPC).

Building Control need this evidence before they will sign off the work. Running the calculation at design stage also means any compliance issues show up on paper, while they are still cheap to change, rather than once the build is underway.

You will usually need a SAP Calculation if you are:

Building a new home. A full SAP at design and as-built stage, plus the EPC, for every new dwelling.
Converting a building into a dwelling. A material change of use, such as a barn, office or agricultural building becoming a home.
Building an extension that is heavily glazed or cannot meet the standard limits on its own (more on this below).

Extensions: Do You Need a Full SAP Calculation?

Often not. Most extensions can prove Part L compliance through a simpler, cheaper route, from £95. We will tell you which one your project needs.

Reference Method

The simplest route for standard extensions. It demonstrates compliance by checking your new elements and glazing against the reference values in the Building Regulations. Ideal when your extension has a normal amount of glazing.

Area Weighted U-Value

For extensions with more glazing than the standard allowance, such as bi-folds, sliding doors, picture windows or roof lanterns. It averages the U-values across all the new elements, so better-performing walls, floor and roof can offset the extra glass.

Full SAP Calculation

When an extension is very heavily glazed, or the simpler routes will not pass, a whole-house SAP compares the extended home against a compliant reference. It gives the most design freedom.

Not Sure Which You Need? Get a Quote →

Common Questions

What information will you need from me?

Floor plans, elevations, sections, and a basic specification (insulation, windows, heating, ventilation). We will walk you through it on the call. If anything is missing, we will tell you exactly what we need.

Do I need a Design SAP and an As-Built SAP?

Usually yes. Design SAP is for Building Control before work starts. As-Built SAP is for sign-off at completion and generates the EPC. Some projects only need one stage, and we will advise.

What if my design does not pass?

Common on first pass. We will tell you exactly what to change and rank fixes by cost and impact, so you are not guessing or over-specifying.

Will Building Control accept your reports?

Yes. All reports are produced by an Elmhurst-accredited OCDEA and lodged on the government register. Accepted by Building Control nationwide.

Ready to get your SAP Calculations sorted?

Leave your details and your SAP assessor will get back to you with a fixed price quote.

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