SAP Calculations for Extensions and other 'Notifiable Works'

Extending or altering domestic property? You may need a SAP Calculation for your Building Regulations submission.

The Building Regulations provide guidance on the thermal performance of extensions, 'material change of use' applications and alterations but do allow for flexibility if there is a design which does not strictly meet the requirements. We can assist with calculations in any of these scenarios.

Simply call us today for a quote, then send us your plans and specifications.

 Contact us now for a free quotation.


Area Weighted U Values and Substantially Glazed Extensions

The most common scenario of the extensions above is the 'Substantially Glazed Extension'.

If your extension has more than 25% of the floor area of the extension as glazing you may not comply with Building Regulations but there will be a solution. You will need us to model the house and extension against a 'notional' dwelling and find a solution that works best for you.

Coles Knapp have provided many such calculations and can meet strict deadlines to ensure that any proposed work is not delayed.


Contact us now for a free quotation.

energy performance certificates | commercial epc | code sustainable homes | chester | manchester energy performance certificates | commercial epc |code sustainable homes | chester | manchester

"We find the team to provide a friendly, professional and efficient service."

Mr Burnell, Estate Agent, North Wales

"We have used the North Wales office on our various properties and have found them to be extremely well organised, professional and a friendly team to deal with. We will definitely use their services again."

Gary Poole, Contractors and Developers, North Wales

Contact Us by Phone

0844 848 2969

Let us call You

Your Name

Your Phone Number (inc. area code)

Time to Call