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Achieving Part L1B Compliance for Conversions/Extensions

Make sure your conversion/extension complies with Part L1B of the English and Welsh building regulations.

DSJ Planning and Design can guide you through the process.


Helping you to avoid the risks

You may not be aware that all conversions and extensions require some SAP input to prove that they meet the current regulations in relation to the envelope U-values and sometimes the area of glazing/openings. Very often it has to be proved that the CO2 emissions from an extended dwelling with a large glazing area are no worse than those of a dwelling plus an extension that complies with the 25% glazing allowance as stated in the Building Regulations, especially with Part L1B, the SAP calculation should be carried out before work commences and in most cases Building Control will insist on receiving a calculation before they will pass a building Regulation application. To start the work under a Building Notice can be very risky and expensive if the conversion fails compliance at the “As Built” stage.

With conversions Building Control will require an “As-Built” SAP calculation and EPC before they can provide their completion certificate.

Brief guide to the processs
  • After initial discussions by telephone or email, documents can be forwarded to us by email (pdf) or post.
  • A quotation will be supplied (if required) and if this is acceptable a completion date and invoice will be supplied.
  • Advice will be provided on any changes to the specification that may be required in order to comply with the regulations
  • Design SAP calculations will then be supplied upon receipt of payment
  • On completion we will supply you with a list of “As-Built” information that we will require in order to obtain the EPC. 

Why choose DSJ Planning & Design?
  • 12 years experience with SAP calculations
  • Full UK coverage
  • 35 years experience with building design
  • Fee quotation with no obligation
  • Free impartial advice 

If you are planning a New Build please visit dsjplanninganddesign.co.uk for information on our services.