Substantially Glazed Extension

Modern glass extensions are increasing in popularity and make desirable additions to any home. However, these require additional proof of compliance to Part L of the Building Regulations. 

We can carry out design reports to help your designer obtain Building Regulations approval and advise you on any changes that are required to obtain this.

By ensuring the calculations are right at the beginning of the project, this will ensure that you do not have any complications throughout the construction process. There are two options for the calculations available, we can provide an area weighted calculation for the extension or should this not be appropriate, we will use SAP calculations for comparison against a nominal extension.

Our assessors will ensure that your dream extension complies with building regulations. We will supply an extensive report with a letter of recommendation to Building Control and full supporting calculations. Please contact us via our building consultancy energy enquiry form for further details.

Glazed extension FAQs

  • Are the calculations mandatory?
    No, these calculations are carried out to show compliance with Regulation L of the Building Regulations, where the amount of glass exceeds 25 percent of the floor area.
  • Which buildings need to have the calculations?
    All extensions where the glass exceeds 25 percent of the floor area.
  • When do the calculations need to be done during the construction process?
    Right at the beginning of your project, at the design stage, before construction starts.