SAP Calculations for Conversions

SAP calculations are required for all new dwellings that are created from the conversion or subdivision of an existing building or structure.

Our highly experienced and fully accredited SAP Assessors offer unrivalled customer support and technical consultation focused on providing cost-effective and practical solutions to achieving compliance with Part L1B of the Building Regulations.

SAP Calculations for Conversion Projects by EPS Group

At EPS Group, we are interested in forming ongoing partnerships with property professionals and self-builders by offering unrivalled customer support and technical consultation, which can be relied upon.

As part of this commitment, our SAP Calculation service includes all required advice and recommendations to ensure that your conversion project passes with Part L1B of the Building Regulations (or regional equivalent) in a practical and cost-effective manner.

For more information relating to SAP Calculations, please explore the Frequently Asked Questions below.

To discuss your conversion  SAP Assessments further, please contact us on 0115 7270599 email us at, or complete our enquiry form.

When are SAP Calculations for Conversions required?

A SAP Calculation should be provided for development projects that result in the creation of a new dwelling as a result of a material change of use or when there has been a change of energy status.

Examples of material change of use include:


  • Development projects that result in the finished building being used as a dwelling where it previously wasn’t. This includes barn conversions and the conversion offices to self-contained flats. 
  • Instances where changes to the internal configuration of a building result in an increased number of dwellings. This includes the conversion of houses to flats or the reconfiguration of an existing development of flats to create additional units.
Residential Flat Subject to SAP Calculation

change in energy status occurs when a previously unheated space is subsequently designed to be heated or conditioned, such as the conversion of garage space or workshop to a residential dwelling. Energy status changes often occur in conjunction with material changes of use.

Conversion SAP Calculation – Frequently Asked Questions:

How do I obtain an Energy Performance Certificate for a Conversion Project?

New dwellings that have been created as a result of a material change, or a change in energy status, require an On Construction Energy Performance Certificate to support the sign off from Building Control.

The On Construction Energy Performance Certificate is derived from a full SAP calculation, which is also required to demonstrate compliance with the Building Regulations.

It should be noted that issuing On Construction Energy Performance Certificates is outside the standard competencies of Domestic Energy Assessors who use a simplified version of SAP (RdSAP) to produce Energy Performance Certificates for the existing housing stock based on a non-instructive survey.

What happens if the SAP Calculation fails?

Unlike new build dwellings, there is no requirement for SAP Calculations for conversions to demonstrate compliance with any minimum carbon dioxide emission rates (e.g. DER/TER of Part L1A).

Part L1B does, however, stipulate minimum thermal standards (U-values) for any existing and new construction fabric. Minimum performance efficiencies are also given for heating, hot water and ventilation systems.

When completing a Part L1B SAP calculation, we will advise whether the project specification complies with the minimum requirements of Building Regulations. If any shortfalls or issues are identified, we will also recommend appropriate specification changes as part of our works.

It is also worth noting that additional Government Legislation has introduced a Minimum Energy Efficiency Standard for rental properties which makes it illegal to let a dwelling in England and Wales with an EPC rating of an F or G.

It is therefore vital to appraise the predicted EPC rating early within a project to ensure that the final EPC rating will not impact on the marketability of the dwelling on completion.

How can EPS Group help with SAP Calculations?

There are many reasons to appoint EPS Group to provide your SAP Calculations

How can EPS Group help with SAP Calculations?

At EPS Group, we are interested in forming ongoing partnerships with property professionals and self-builders by offering unrivalled customer support and technical consultation, which can be relied upon.
As part of this commitment, our SAP Calculation service includes all required advice and recommendations to ensure that your project passes with the appropriate Building Regulations in a practical and cost-effective manner.

Don’t let compliance obligations hold you back! Our Energy Consultants and certified Assessors have the experience to understand your challenges, and the expertise to meet them on your behalf.


Highly Experienced

EPS Group have been providing energy consultancy and testing services since 2007. Our three directors have more than 40 years of combined industry experience ensuring that your project is in safe hands.


Competitive Pricing

We provide transparent, competitive, all-inclusive fixed fees with significant discounts available for developments with multiple units.


Expedited Service Available

We appreciate that developments move fast. If you require energy calculations or pressure testing urgently, give us a call and we will try our best to help.


One Stop Solution

From planning to completion we provide an extensive range of complementary services which helps to simplfiy our client’s compliance obligations.


Independent Advice

We only provide energy compliance services. With no materials to sell or commissions to earn, you can be confident that we will aim to provide you with the most economic and feasible solutions to achieving compliance.


Fully Accredited Team

Our Energy Consultants and Technicians are all fully accredited across a range of disciplines. You can therefore rely on the advice and services that they provide.


Client Focused

We tailor our services around you and your bespoke requirements. This is not an industry where a one-size fits all approach should be used.


Ongoing Technical Support

Plans and specification change during the construction process. We therefore provide technical support throughout the duration of a build in order to prevent any regulatory problems arising at completion.

EPS Group: A Partner for those in the Construction Industry

We value the importance of a solid working relationship with those in the construction industry, and for many, we serve as the reliable go-to-company to entrust from the planning stage of a development through to completion.

What Our Clients say:

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Let’s discuss your SAP project!

Jual Ahmed
Jual Ahmed
Excellent service from start to finish. I would highly recommend and will definitely use again. Thank you!
A great service and attended within a week of request. Polite knowledgeable engineer who completed the test quickly and efficiently...Thank you EPS
Steve Naylor
Steve Naylor
EPS group undertook the initial SAP design assessment, then the as-built assessment for my new property, including air test. They were super-responsive and made the appointment for the air-test within a few days of the request. The certificates were issued very promptly and they helped me through the process (I had never done this before). Really recommend them.
Nick Collingridge
Nick Collingridge
Great service from EPS Group. Their operative was friendly, efficient and very helpful. He carried out his survey quickly and then spent time walking round the property with me pointing out all the points at which air was infiltrating. He also passed on some invaluable tips about the best way to attend to the detailing of aspects of a property's structure to maximise air tightness. I am altogether very satisfied with the survey.
Mark Blood
Mark Blood
Have worked with EPS for several years now in connection with all of our energy assessment requirements. Extremely efficient service at very competitive fees and always available to offer advice on achieving compliance. Would definitely recommend.