SAP Calculations (Heat Loss Assessments) are a useful way of demonstrating that highly glazed extensions, orangeries and garden rooms comply with the requirements of Part L1B of the Building Regulations via the Design Flexibility Criterion. This is something which is being requesting increasing more by Building Inspectors as a result of the growing trend for homeowners specifying Bifold doors and roof lanterns within their extension projects.

Why Choose EPS Group?

Our highly experienced SAP Assessors have provided SAP calculations on thousands of hioghly glazed extension projects with varying degrees of construction complexity and site limitations and to date we have a 100% record in proving compliance with Part L1B of the Building Regulations.

We are therefore confident that you will not need to compromise your design in order to meet the requirements of Building Regulations if you instruct us to undertake heat loss assessments on your proposed (or completed) extension project.

There are many reasons to appoint us to provide your SAP Calculations or Heat Loss Assessments including:
  • Highly Experienced SAP Assessors
  • Fully Inclusive Fixed Price Fees
  • High Quality Customer Driven Service
  • Extensive Part L1B Compliance Advice and Technical Support
  • U-Value Calculations Included
  • Expedited Service Available On Request

At EPS Group we pride ourselves on forming constructive working partnerships with our clients. 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.

Read More About SAP Calculations for Extensions

SAP Calculations for Extensions

Essentially two alternate extension SAP calculations are produced; the first is based on the existing property with a conventional extension of the same dimensions as the proposed works and a conventional level of glazing. This ‘Notional’ SAP calculation provides a calculated level of annual carbon dioxide emissions which in turn provides a target threshold for the proposed works.

A second extension SAP calculation is then prepared, based on the existing house and the specification of the proposed extension, sun room or conservatory. The associated annual carbon dioxide emissions are then compared to the previously calculated target rate.

If the proposed extension carbon dioxide emissions are less than the target threshold, then the works are deemed to comply with Part L1B of the Building Regulations via the Design Flexibility Criterion without any additional requirements. In such instances the alternate extension SAP calculations are prepared with a short report for submission to Building Control.

Conversely, if the proposed extension carbon dioxide emissions are greater than the calculated target threshold, then trade-off improvements will be required to either the extension specification or the existing house as a means offsetting the additional heat loss associated with the extra levels of glazing within the proposed extension above the standard threshold detailed within the Building Regulations.

Examples of commonly recommended improvements include additional depths of insulation to the extension floor or roof, improved glazing specificiations, top up loft insulation or cavity wall insulation to the existing property, or improvements to the existing heating system.

The SAP assessment for a conservatory or extension should ideally be completed as soon as the architect or contractor has finalised the proposed build specification for the extension works, since if the SAP calculations result in an initial compliance failure, it is far easier to recommend subtle amendments to specific insulation thicknesses or material amendments before any work has commenced.

 Why not discuss your project  with a member of our team?

Call us today on 0115 727 0599.