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SAP Calculations for Conversions
Part L compliant SAP Calculations for conversions and change of use projects, completed by Elmhurst accredited assessors. Fast turnaround for clients nationwide.
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SAP Calculations for Conversions
Does my conversion need SAP?
Usually yes - when a building becomes a dwelling or you create a new flat, SAP is required.
What types of conversions?
Garages, barns, commercial buildings, lofts becoming separate dwellings, annexes.
How much does it cost?
From £170 per dwelling. Complex barn conversions from £250.
How long does it take?
Most completed within 2-4 working days once we have your drawings.
What if it fails?
We provide clear recommendations. Revisions included until you pass.
Do you lodge the EPC?
Yes. As-Built SAP + EPC at completion, reduced rate if we did Design SAP.
Not sure if your project needs SAP? Send us your plans and we'll confirm what's required - no charge.
What Is a SAP Calculation for Conversions?
A SAP calculation for a conversion is an energy assessment used to show that a change of use project will meet the Part L energy efficiency standards.
Conversions are treated differently to new build homes; there is no overall carbon or primary energy target to hit, but Building Control still need clear evidence that the fabric and services are reasonable for the new dwelling created.
Under Approved Document L, compliance for conversions can be shown in two ways. The first is an elemental approach using limiting U-values for new thermal elements and minimum efficiencies for building services. The second is to use a SAP conversion calculation to demonstrate that the dwelling has acceptable primary energy, carbon emissions and fabric performance.
The SAP conversion calculation looks at the existing structure, any new or upgraded walls, floors and roofs, the glazing and doors, and the heating, hot water and ventilation systems serving the finished dwelling. We make sure new thermal elements meet the limiting U-values for existing dwellings and that the overall conversion is reasonable and compliant for Building Control.
Which Types of Conversions Need a SAP Calculation?
Conversion SAP calculations are commonly needed for a wide range of change of use projects. If you are turning an existing building into one or more homes, it is very likely that a SAP conversion calculation will be required for Building Control sign off.
- Garage conversions to habitable rooms - where an attached or detached garage becomes a living space, annexe or separate dwelling.
- Barn and agricultural building conversions - barn conversion SAP calculations check new thermal elements, glazing and heating so that rural homes meet current Part L standards.
- Commercial to residential conversions - shops, offices and other commercial buildings converted into flats or houses usually need a SAP for each new dwelling created.
- Loft conversions forming new dwellings - some loft conversions that create a new self-contained dwelling or flat will require a SAP calculation for conversion.
- Outbuildings and annexes - outbuildings and annexes that become separate homes or long-term living spaces can fall under SAP for conversion and change of use.
What Is Included in Our Conversion SAP Service
Our SAP service for conversions and change of use projects is designed to give clear answers when the rules can feel confusing. We assess the existing building, your proposed upgrades and the new services to help you achieve a comfortable and compliant dwelling.
- SAP conversion calculations for garages, barns, commercial buildings, lofts and annexes
- Assessment of existing elements and new thermal elements including walls, floors and roofs
- Checks against limiting U-values for existing dwellings in Part L
- Review of glazing, doors and roof lights to check overall heat loss and solar gains
- Heating, hot water and ventilation system checks against Building Regulations requirements
- Clear pass or fail summary with practical recommendations where improvements are needed
- Reasonable design stage revisions included
- As-Built SAP and EPC at completion as an optional add-on
- Email support for your architect, builder and Building Control officer throughout the project
Pricing for Conversion SAP Calculations
SAP Calculations for conversions are priced per dwelling with fixed, transparent fees. The cost depends on the type and complexity of the conversion.
Standard Conversion SAP
From £170
Per dwelling for straightforward conversion SAP calculations where the building layout and specification are simple.
Complex / Barn Conversions
From £250
For larger or more complex conversion SAP projects such as barn conversions and commercial to residential schemes.
As-Built SAP + EPC
From £80
Reduced fee add-on where we have already completed the design stage conversion SAP for your project.
How the Conversion SAP Process Works
The SAP process for conversions is straightforward. We focus on giving clear advice so that you, your architect and your builder can keep the project moving without delays from Building Control.
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1
Send us your conversion drawings and details
Upload your floor plans, elevations, sections and site plan along with any details you have on existing and proposed construction, windows and doors, heating and ventilation.
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2
We complete your SAP conversion model
We build a SAP conversion calculation that reflects the existing building and your proposed upgrades. We check new thermal elements, glazing and services against the relevant Part L requirements.
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3
You receive your SAP report for Building Control
Once the SAP for conversion meets the required standards, we issue your design stage SAP report and Part L documentation for Building Control.
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4
As-Built SAP and EPC at completion
When the conversion is finished we can update the SAP with the final specification, air test results and photographic evidence, then lodge the EPC.
What We Need for a Conversion SAP Calculation
Conversions and change of use projects often start from imperfect information. We work with what you have and help you fill in the gaps so that the SAP calculation for your conversion is both realistic and compliant.
- Floor plans with dimensions and room labels for the existing building and proposed layout
- Elevations and sections showing existing and proposed openings, floor levels and roof form
- A site plan showing orientation, access and any attached or adjacent buildings
- Details of existing construction where known, for example wall, floor and roof build ups
- Proposed insulation upgrades to new thermal elements and any upgraded existing elements
- Window and door schedule with sizes, types and U-values if available
- Heating and hot water system specification, including boiler or heat pump models and controls
- Ventilation information, such as extractor fans, dMEV, MEV or MVHR systems
- Any proposed renewable technologies, such as solar PV or connection to a low carbon heat network
Why Choose Us for Conversion SAP Calculations
Conversion projects rarely fit a standard pattern. You need a SAP assessor who understands how to balance existing construction, new thermal elements and modern services so that the finished dwelling meets Part L without unnecessary cost.
- Elmhurst accredited OCDEA with experience in a wide range of conversion and change of use projects
- SAP conversion calculations for garage, barn, commercial to residential, loft and annexe projects
- Fixed, transparent pricing with no hidden extras or rush fees
- Fast turnaround times and clear communication throughout
- Practical recommendations that work on real sites, not just on paper
- Design stage and As-Built services so you can use a single assessor from start to finish
- Reports written in clear language that Building Control officers can follow with ease
Conversion SAP Frequently Asked Questions
Does my conversion need a SAP calculation?
What drawings do I need to send for a conversion SAP?
What are new thermal elements in a conversion?
Do all loft conversions need a SAP calculation?
What happens if my conversion fails the SAP calculation?
Do you provide the EPC at completion?
Will Building Control accept your SAP conversion reports?
Ready to get your Conversion SAP?
All SAP calculations completed by an Elmhurst-accredited OCDEA and accepted by Building Control nationwide.