SAP Calculations

EPCs for Domestic & Non-Domestic Buildings

SAP calculations are a critical requirement for demonstrating compliance with Building Regulations Part L for new dwellings in England and Wales. Whether you’re building a new home, converting an existing property, or working on a residential development, accurate SAP calculations are essential to achieve Building Control approval and move your project forward.

At [Your Company Name], we provide fast, accurate, and fully compliant SAP calculations to support planning, design, and construction stages. Our reports are tailored to your project, aligned with the latest Part L regulations, and accepted by all local authority and approved Building Control bodies.

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What Are SAP Calculations?

SAP stands for Standard Assessment Procedure. It is the UK government’s approved methodology for assessing the energy performance of residential buildings.
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SAP calculations evaluate how a dwelling uses energy for:

Space heating
Hot water
Lighting
Ventilation

They also assess carbon emissions and energy efficiency based on the building’s construction, insulation, heating systems, and renewable technologies.

The outcome of a SAP calculation determines whether a dwelling complies with Part L of the Building Regulations and directly feeds into:

BRUKL reports
Energy Efficiency Ratings (EER)
Carbon Emission Rates (DER vs TER)
EPC production

When Are SAP Calculations Required?

SAP calculations are required for:

New Build Dwellings

All new residential buildings must undergo SAP calculations to demonstrate compliance with Part L before construction is completed.

Conversions

- Barn conversions - · Office-to-residential (Class MA) - · Change of use developments

New Dwellings Created Through Extensions

Where an extension creates a new self-contained dwelling, SAP calculations are mandatory.

Building Control Submissions

SAP reports are required at both:

Design Stage (Pre-Construction)
As-Built Stage (Post-Construction)

SAP Calculations & Part L Compliance

The current Part L 2021 regulations set stricter targets for energy efficiency and carbon emissions than previous versions. SAP calculations are used to confirm that your dwelling meets these targets by comparing:

DER (Dwelling Emission Rate)
TER (Target Emission Rate)

&

DFEE (Dwelling Fabric Energy Efficiency)
TFEE (Target Fabric Energy Efficiency)

To pass, the calculated dwelling values must be equal to or better than the target values. Our SAP assessors don’t just run calculations — we actively optimise your design to help you pass first time, saving you time, redesign costs, and construction delays.

Design Stage SAP Calculations

Design stage SAP calculations are produced using architectural drawings and specifications before construction begins.
What’s Included:

Full SAP assessment using approved software
Part L compliance analysis
U-value checks for walls, roofs, floors, windows, and doors
Heating, hot water, and ventilation efficiency assessment
Renewable technology evaluation (solar PV, heat pumps, etc.)
BRUKL and compliance documentation for Building Control

Why Design Stage SAP Is Important

Producing SAP calculations early allows:

Identification of compliance issues before construction
Cost-effective design adjustments
Avoidance of expensive remedial work later

If the initial design fails Part L, we provide clear recommendations to achieve compliance with minimal impact on your project.

As-Built SAP Calculations

As-built SAP calculations are completed once construction is finished and reflect what has actually been installed on site.

Information We Use:

Final construction details
Installed heating and hot water systems
Ventilation strategy
Airtightness test results (where applicable)
Renewable energy systems

Outputs:

Final SAP report
As-built Part L compliance confirmation
Data for EPC production
Documents required for Building Control sign-off

Without accurate as-built SAP calculations, Building Control will not issue a completion certificate.

SAP Calculations for Developers & Builders

We regularly work with:

Property developers
House builders
Architectural practices
Design & build contractors

Our service is structured to support:

Single dwellings
Small housing developments
Large multi-plot sites

For developments, we offer:

Plot-by-plot SAP calculations
Specification optimisation across multiple units
Consistent compliance strategy to reduce costs
Fast turnaround to keep build programmes on track

SAP Calculations for Homeowners

If you’re self-building or converting a property, SAP calculations can feel complex. We take care of the technical details and guide you through the process in plain English.

We’ll explain:

What’s required for compliance
Where changes may be needed
How to meet regulations without unnecessary expense

Our goal is to make compliance simple, stress-free, and affordable.

Common SAP Calculation Issues (And How We Solve Them)

Failing Part L

We identify the most cost-effective improvements, such as:

Insulation upgrades
Heating system efficiency improvements
Modest renewable additions

Over-Specification

We prevent unnecessary overspending by avoiding excessive or unneeded measures.

Delays to Building Control

We provide clear, compliant reports accepted by Building Control first time.

Poor Coordination

We work directly with architects, builders, and consultants to ensure all information aligns.

What Information Do We Need?

To produce SAP calculations, we typically require:

Architectural drawings (plans, elevations, sections)
Construction specifications
Heating and hot water details
Ventilation strategy
Window and door specifications

If anything is missing, we’ll let you know exactly what’s needed — no guesswork.

Why Choose Us for SAP Calculations?

Qualified and experienced SAP assessors

Fully compliant with latest Part L regulations

Fast turnaround times

Practical, build-friendly advice

Accepted by all Building Control bodies

Competitive, transparent pricing

The focus is on accurate, reliable EPCs with no last-minute issues.

SAP Calculations & EPCs

SAP calculations form the backbone of Energy Performance Certificates (EPCs) for new dwellings. Once your as-built SAP is complete, EPCs can be produced quickly and accurately using the final data.

If required, we can provide:

SAP calculations
EPCs
BREL / Part L documentation
as a single, streamlined service.

Professional SAP Calculations for Building Regulations Compliance