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New Dwellings - Conversions - Extensions
"Part-L" SAP Calculations
Energy Statements
From £99 (No VAT Added)
Whole UK Covered
Fast Lead Times

What is a Part L SAP Calculation?

Part L SAP Calculations (Standard Assessment Procedure) constitute a crucial element of the Building Regulations, applying to all newly built residential properties throughout the UK. Mandated since 1995, the need for a SAP Rating, as per Part L of the building regulations, has become a firmly established practice embraced by the majority of developers.


Interested in discovering how we can help you save both time and money?

OCDEA Assessor

SAP Calculations serve three primary functions:

SAP calculations serve several key purposes:

  • They determine a SAP Rating, which quantifies the energy-related operational costs linked to a dwelling.

  • They offer evidence of compliance with Part L of the building regulations.

  • They enable the creation of an Energy Performance Certificate (EPC).

It's important to mention that SAP calculations might also be required for conversions or extensions, subject to slightly different regulations, and Scotland maintains its own specific requirements.

SAP Calculation Factors

  • SAP calculations play a crucial role in quantifying two essential factors: the Dwelling Emission Rate (DER) and the Dwelling Fabric Energy Efficiency (DFEE). These figures form the foundation for establishing:

  • A Target Emissions Rate (TER)
    A Target Fabric Energy Efficiency (TFEE) rate
    In England, it's imperative that the DER and DFEE values are lower than the TER and TFEE calculations. Conversely, in Wales and Scotland, the focus primarily lies on DER measurements.

  • If you're considering selling or renting out your property, completing SAP calculations is essential for obtaining an Energy Performance Certificate (EPC), which is a legal requirement for all new builds.

  • Should your SAP calculation indicate that your dwelling emission rate doesn't meet compliance standards, there's no need to worry! Our assessors are available to offer practical advice and guidance on necessary adjustments to enhance your building's energy efficiency. This includes minimizing energy consumption, optimizing thermal elements, refining ventilation systems, meeting CO2 emissions targets, and integrating renewable technology components.

  • Addressing these areas can significantly improve your dwelling's energy profile, leading to reduced fuel costs and the acquisition of the coveted energy performance certificate.

How much are SAP Calculations?

  • SAP Calculations and assessments begin from just £99 per unit, varying depending on the complexity and size of the building, lead time only around three days. 

  • Our pricing structure is tailored to the specific dimensions and intricacies of your dwelling. We believe in offering bespoke quotes on an individual basis to ensure you receive the most competitive pricing possible.

  • Get in touch with us today and provide details about your plans or accredited construction information. Our energy assessment prices include a comprehensive package, encompassing lodgement and registration fees, expert guidance on building regulations compliance, iterative improvements, and the issuance of all necessary supporting documentation.

Important information to help you plan for your SAP Assessment

  • SAP assessments play a pivotal role in comprehending your design. Ideally, we require accredited construction details and comprehensive, up-to-date drawings, preferably in electronic format.

  • Please note that we are unable to utilize photographs, rough sketches, or watercolors. You may be requested to furnish a fairly detailed specification of your construction plans. This enables us to gauge the level of development in your design, determine fixed aspects, flexible elements, and areas that remain uncertain. With this information, your assessor can provide guidance and assistance to fill in any gaps.

New Build Sap

When are SAP Calculations for Conversions needed?

SAP Calculations for Conversions become necessary when a building undergoes a transformation from a non-domestic use to a domestic one, such as converting from a shop or office to a house, which is classified as a 'Material Change of Use' or a Change of Energy Status. These calculations evaluate the energy efficiency of the proposed alterations and offer recommendations for enhancements where required.

When considering changes in material use during a conversion, you may be examining aspects such as:

- Insulation materials for walls, floors, and roofs

- Window glazing types and frames

- Heating and hot water systems, including boilers and radiators

- Ventilation systems to ensure adequate airflow while maintaining energy efficiency

- Lighting fixtures and fittings, focusing on energy-efficient options like LED bulbs

- Renewable energy technologies like solar panels or heat pumps for sustainable energy generation.

✔️Transitioning a building from a non-residential or commercial property to residential use

✔️Adding an additional flat to the existing structure

✔️Increasing the number of dwellings within one building.

Transitioning to a new energy status may become necessary when an unheated area or building is being newly designated for heating. Additionally, changes in the usage of a building could lead to alterations in its energy status. We're here to assist you throughout this process, ensuring that you are well-informed and up-to-date on everything related to the modification of your energy status.

Should any issues arise during the delivery of your SAP Calculations, rest assured that our experienced team will address them efficiently. We provide peace of mind and swift solutions, enabling you to proceed smoothly with your plans.

Our process – how we ensure you meet the required standards

We recognize the significance of maintaining compliance with conversions, which is why we utilize SAP Calculations to verify if U-Values meet the standards outlined in all technical documents approved by the government. If these values fall short of expectations, we want to assure you that our team will provide guidance on the best course of action.

Moreover, we take extra measures to ensure that lighting and heating levels surpass the minimum requirements. If adjustments are necessary for compliance, rest assured that we will assist you every step of the way.

Simply download and complete our checklist, providing all the required information. We offer a fast and efficient turnaround for SAP calculations on extensions.  

Helpful information you may need to supply?

For a smooth and efficient SAP calculation process, please ensure you provide the following information:

Floor plans, sections & elevations.

Orientation details such as a site plan of existing elements.

Construction specification for existing walls, new structures, roofs, and floors.

Detailed specifications for all windows.

Information on primary & secondary heating systems

Details about any renewable technology (if applicable).

If you have any questions or need further assistance, please don't hesitate to call us at 0800 999 1151. We're here to help!

What is included?

We offer a comprehensive range of services to ensure compliance with Building Regulations:

Provision of all SAP calculation documentation required from Design (PEA) to On Construction stage.

Additional recommendations provided if needed to ensure a successful outcome every time available.

Ongoing advice and support throughout the entire process available.

Quick turnaround times to meet your project deadlines.

We are more than willing to liaise directly with your Builder, Architect, or Building Control Officer for seamless coordination.

Your satisfaction and compliance are our top priorities. If you have any further inquiries or need assistance, please feel free to reach out.

  • What are SAP Calculations?
    SAP stands for ‘Standard Assessment Procedure’ and is the government’s method for calculating the energy performance of dwellings. These calculations are only necessary for residential properties. The calculations determine a Target Emissions Rate (TER) and a Target Fabric Energy Efficiency (TFEE) rate.
  • How much is a SAP Calculation?
    Our fees are typically based upon the size and complexity of a dwelling. We do prefer to offer a bespoke quotation on a job-by-job basis to give you the best price – So get in contact and send us your plans today!
  • Can I do a SAP Calculation for conversions myself?
    SAP Calculations must be carried out by an On Construction Domestic Energy Assessor or OCDEA, working with approved Government program. The Assessor must be certified under one of several accreditation schemes and is regularly audited to keep their certification.
  • What is required for a SAP Assessment?
    Your Assessor would advise you of exactly what is needed. Typically you would need the following: Floor plans, sections & elevations Orientation e.g. site plan Construction specification of walls, roofs and floors Specification for all windows Primary & secondary heating systems Renewable technology (if any)
  • What happens if my design fails its SAP Assessment?
    If your design fails its SAP Assessment, then you will need to revise the design to meet the requirements. Depending on the extent of the changes required, you may need to go through the assessment process again. In some cases, you may need to have additional testing done to verify the design’s performance. The SAP Assessor will provide guidance on the necessary steps to make your design meet the requirements.
  • Are SAP Calculations the same as an Energy Performance Certificate?
    No, SAP Calculations and Energy Performance Certificates (EPCs) are not the same. SAP Calculations are used to determine the energy performance of a building and are used in the UK to comply with Building Regulations. An Energy Performance Certificate is a certificate that shows the energy efficiency of a building and is required when a building is built, sold, or leased. The EPC uses the results of the SAP calculation to give the building a rating from A to G, with A being the most energy efficient and G being the least. The EPC also provides recommendations for improving the energy efficiency of the building.

SAP Calculations for all your building projects

Embarking on a New Build or Conversion journey? Explore a range of specialized services tailored to your project's needs. Our experts offer a suite of offerings, from Energy Statements, "Part O" Reports,  PSI & U-Value Calculations, and more.


Let's elevate your project together. Reach out today to discover the possibilities.

New Build EPC.jpg

Part L1A

SAP Calculations for New Builds

Nowadays, every new dwelling must undergo a SAP calculation during the design stage to show compliance with Part L1A of the Building Regulations.

Extension EPC.jpg

Part L1B

SAP Calculations for Extensions

When constructing an extension with glazing covering over 25% of the floor area, we can conduct SAP Calculations to validate compliance with Part L1B Building Regulations.

Conversion EPC.jpg

Part L1B

SAP Calculations for Conversions

Indeed, as per current regulations, all newly constructed dwellings must undergo a SAP calculation during the design phase to showcase adherence to Part L1A of the Building Regulations.

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