SAP Calculations for Conversionsfrom £100
SAP calculations for barns, commercial buildings and other material changes of use creating homes. Clear advice and reports ready for Building Control.
- Barn conversions, commercial conversions and new flats
- Design Stage and As-Built assessments
- SAP assessment and Energy Performance Certificate
- Practical advice for working with existing structures
Prefer to talk? Call us on 0333 567 9010.
What Is a SAP Calculation for Conversions?
A SAP Calculation for a conversion shows that a change-of-use project meets the Part L energy efficiency standards when an existing building becomes a home.
A material change of use is assessed differently from a new build. We check the applicable Part L requirements for the building fabric and services, rather than applying the new build carbon and primary energy targets. Under Approved Document L, retained walls, floors and roofs have different requirements from new or replaced elements. We check the appropriate insulation, glazing and building services standards for your conversion.
We assess the existing structure, any new or upgraded elements, the glazing and doors, and the services for the finished dwelling, then produce the SAP and EPC that Building Control need to sign off the conversion.
Which Conversions Need a SAP Calculation?
If you are turning an existing building into one or more homes, a conversion SAP is very likely required. Common projects include:
- Separate dwellings, where an existing building becomes a self-contained home.
- Barn and agricultural conversions, checking new thermal elements, glazing and heating so rural homes meet current standards.
- Commercial to residential, where shops, offices and other buildings become flats or houses, usually needing a SAP for each new dwelling.
- Houses divided into flats, where the project creates additional dwellings.
- Outbuildings and annexes that become separate homes or long-term living space.
Not sure if yours qualifies? Send your drawings and a short description and we'll confirm what is required before you commit.
What's Included
Every conversion SAP includes:
- SAP conversion calculations for barns, commercial buildings and separate dwellings
- Assessment of existing and new thermal elements (walls, floors, roofs)
- Checks against the limiting U-values for existing dwellings
- Review of glazing and doors for heat loss and solar gain
- Heating, hot water and ventilation checks
- Clear advice on the applicable Part L requirements and any specification changes needed
- Reasonable design stage revisions included
- As-Built SAP and EPC available at completion
How the Conversion SAP Process Works
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1
Send Your Drawings and Details
Upload floor plans, elevations, sections and a site plan, plus what you know about existing and proposed construction, glazing, heating and ventilation.
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2
We Build Your Conversion SAP
We model the existing building and your proposed upgrades, checking new thermal elements, glazing and services against Part L.
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3
Report for Building Control
Once it meets the standards, we issue your Design Stage SAP report and Part L documentation.
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4
As-Built and EPC
When the conversion is finished, we update the SAP with the final specification and supporting evidence, then lodge the EPC.
What We Need
Conversions often start from imperfect information. We work with what you have and help fill the gaps:
- Floor plans with dimensions for the existing building and proposed layout
- Elevations and sections showing openings, floor levels and roof form
- A site plan showing orientation
- Details of existing construction where known (wall, floor and roof build-ups)
- Proposed insulation upgrades to new and existing elements
- Window and door schedule with U-values if available
- Heating, hot water and ventilation specification
- Any renewables, such as solar PV or a heat pump
Unsure on any of these? We can work from reasonable assumptions and refine the SAP as the design develops. Our practical SAP checklist covers it.
Conversion SAP Pricing
As a non-VAT-registered business, SAPgen does not charge VAT. All prices shown are the total payable.
Why Choose Us
Conversions rarely fit a standard pattern. You want an assessor who can balance existing construction, new elements and modern services without unnecessary cost.
- Elmhurst-accredited OCDEA experienced across conversion and change-of-use projects
- Conversion SAP for barns, commercial buildings and new flats
- Fixed, transparent pricing with no hidden extras
- Fast turnaround and clear communication
- Practical recommendations that work on real sites
- Design Stage and As-Built from one assessor
Frequently Asked Questions
Does my conversion need a SAP Calculation?
What drawings do you need?
What are new thermal elements?
Does a loft or garage conversion need a SAP calculation?
What if my conversion specification needs improving?
Do you provide the EPC at completion?
Will Building Control accept your reports?
Planning a Conversion?
Send us your drawings and we'll advise on the best route to compliance and quote a fixed price.