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Building regulations compliance

Conversion SAP Calculations for existing buildings.

SAP assessments for loft, garage and barn conversions and residential changes of use, supporting the Part L evidence required by building control.

Homeowners Architects Developers Conversions
loft conversion
The service

Plan compliance around the realities of an existing building.

Conversions bring existing construction, retained elements and new residential requirements together. SAP modelling establishes the proposed energy performance and Part L evidence.

We review the existing building and proposed works, then explain where the specification may need to change.

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Existing construction and retained elements assessed

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New and upgraded fabric reviewed

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Heating, hot water and ventilation considered

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Clear Part L evidence for building control

Need help?

Not sure exactly what you need?

Send us your drawings, planning information or building control requirements and we can confirm the right assessment for your project.

Who it is for

The right support at the right project stage.

HOME PROJECT

Homeowners

For loft, barn and garage conversions where energy evidence is required.

DESIGN

Architects

Coordinate retained fabric and new construction with the required energy performance.

DEVELOPMENT

Property developers

For barns and other changes of use where residential compliance needs to be demonstrated.

PROJECT STAGE

Technical design

Assess before building control submission and identify where the specification needs to change.

What we assess

Existing conditions and proposed improvements together.

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Existing and proposed occupancy

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Retained and upgraded fabric

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New walls, roofs and floors

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Heating and hot water

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Ventilation strategy

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Thermal bridging assumptions

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Part L performance

How we work

A clear process from information to issue.

01
Step 01

Gather information

We review existing construction, proposed works and the intended use of the building.

02
Step 02

Build the model

We model the retained elements and proposed upgrades to understand the building's performance.

03
Step 03

Resolve compliance

We test practical specification changes where improvements are needed to meet the requirements.

04
Step 04

Issue the assessment

We provide evidence for building control and explain the key assumptions and outcomes.

What you receive

Clear outputs for your project team.

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SAP calculation for the conversion

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Part L compliance output

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Existing and proposed assumptions

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Specification feedback

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Clear evidence for building control

Not sure whether your conversion needs a SAP calculation?

Send us your plans or project information and we can help identify the right assessment and Part L evidence for the proposed works.

FAQs

Common questions

Which conversions can require SAP?

Examples include loft, garage and barn conversions, as well as changes of use where an existing building is being converted into residential accommodation.

How do you assess existing construction?

We review the available information about the existing building and its retained construction, then incorporate the relevant assumptions into the SAP model.

Can retained walls and roofs be included?

Yes. Retained elements form an important part of the assessment, particularly where existing construction differs from the proposed new elements.

When should I arrange the calculation?

Ideally, the SAP assessment should be considered during technical design, before the specification is finalised. This gives the project team time to respond to any requirements identified.