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SAP Calculations, BREL Reports & Part L Compliance

SAP10 Assessments for New Builds, Extensions & Conversions

Fast Turnaround • Elmhurst Accredited OCEA Assessors • Nationwide Service

Planning a new build, extension or conversion? Energy National provides professional SAP calculations, BREL reports and Part L Building Regulations compliance for residential developments across England.

Our experienced On Construction Energy Assessors (OCEA) work closely with architects, developers, builders and homeowners to ensure projects achieve Building Control approval quickly and efficiently.

Whether you are constructing a single dwelling, a block of apartments or converting an existing building into residential accommodation, we provide practical design advice to help you meet compliance at the lowest possible cost.

Our SAP Services

We provide:

✅ SAP10 Calculations

✅ SAP EPCs

✅ BREL Reports

✅ Part L1A Compliance

✅ Part L1B Compliance

✅ U-Value Calculations

✅ Thermal Bridge (Psi) Calculations

✅ Accredited Construction Details (ACDs)

✅ Part O Overheating Assessments

✅ Part F Ventilation Calculations

✅ Part G Water Efficiency Calculations

✅ Air Pressure Testing Coordination

✅ Sound Testing Coordination

✅ As-Built SAP Reports

Why Choose Energy National?

✔ Over 17 years’ experience

✔ Elmhurst Accredited OCEA Assessors

✔ Competitive fixed pricing

✔ Fast turnaround times

✔ Nationwide coverage

✔ Building Control approved reports

✔ Expert design-stage advice to avoid costly redesigns

✔ Support from planning through to completion

Our objective is not simply to produce calculations—we help optimise your design to achieve compliance with the latest Building Regulations while keeping construction costs under control.

What Is a SAP Calculation?

A SAP (Standard Assessment Procedure) calculation measures the energy efficiency and environmental performance of a dwelling.

It demonstrates compliance with Part L of the Building Regulations by calculating:

• Dwelling Emission Rate (DER)
• Target Emission Rate (TER)
• Dwelling Primary Energy Rate (DPER)
• Target Primary Energy Rate (TPER)
• Fabric Energy Efficiency
• Overall Energy Rating
• Carbon Emissions

SAP calculations are required for:

• New build dwellings
• Residential developments
• Self-build projects
• Flat developments
• Barn conversions
• Commercial-to-residential conversions
• Extensions requiring Part L1B compliance

What Information Do We Need?

To complete your SAP assessment, we typically require:

• Architectural floor plans
• Elevations
• Sections
• Site plan and orientation
• Wall, roof and floor construction details
• Window and door specifications (U-values and g-values)
• Heating system specification
• Hot water system
• Ventilation system
• Renewable technologies (Solar PV, ASHP, MVHR, batteries etc.)
• Thermal bridge details or Accredited Construction Details
• Air pressure test certificate (where applicable)

If any information is unavailable, we can advise on suitable assumptions or recommend compliant construction specifications.

Our Process

Step 1 – Send Us Your Drawings

Email your architectural plans and specifications.

Step 2 – Initial Assessment

We review the design and identify any areas that may prevent compliance.

Step 3 – Design SAP Calculation

We prepare your SAP calculations and provide recommendations where improvements are required.

Step 4 – Building Regulations Approval

Your reports are issued for submission to Building Control.

Step 5 – As-Built SAP & BREL Report

Once construction is complete, we prepare the final SAP report, BREL report and SAP EPC.

We Help Prevent SAP Failures

Many projects fail because of:

• Poor glazing specifications
• High thermal bridging
• Incorrect insulation
• Low heating efficiency
• Poor ventilation design
• Air leakage
• Excessive carbon emissions

Our design-stage advice helps identify these issues before construction begins, saving time and reducing expensive remedial work.

Projects We Work On

We regularly provide SAP calculations for:

• Individual new build houses
• Housing developments
• Apartment blocks
• Care homes
• Barn conversions
• Commercial conversions
• Loft conversions
• Large extensions
• Self-build homes

Related Services

Energy National also provides:

• Residential EPCs
• Commercial EPCs
• Air Pressure Testing
• Sound Testing
• Part O Assessments
• Part F Ventilation
• Part G Water Calculations
• U-Value Calculations
• Thermal Bridge Calculations
• Legionella Risk Assessments

Frequently Asked Questions

How much do SAP calculations cost?

Costs depend on the size and complexity of the project. Contact us for a fixed quotation with no hidden charges.

When do I need SAP calculations?

Before Building Control approval for all new dwellings and many conversions.

What is a BREL Report?

A BREL (Building Regulations England Part L) report confirms that the dwelling has been constructed in accordance with the approved energy assessment and Building Regulations.

Do you cover the whole UK?

We provide SAP calculations remotely for projects throughout England.

How quickly can you complete my SAP assessment?

Most projects are completed within a few working days, with urgent services available where required.