Northumberland
Building Regulations for rear extensions in Northumberland
Construction drawings, structural calculations and building control through to the completion certificate. Rear extensions in Northumberland: we cover 10 towns including Blyth, Cramlington and Ashington, with design, approvals and the build under one contract.
Terraces and semis are typical around Northumberland. On terraces a single-storey rear extension across the back yard is usually the practical choice; semis often have room for more.
What does it cost in Northumberland?
As a guide, £2,500–£5,500 including VAT. These are guide ranges; the written quote after the survey is the figure that counts.
What approvals does it need in Northumberland?
Planning and Building Regulations are separate in England: even a permitted development extension is inspected for foundations, drainage, structure, insulation, fire safety and ventilation, through the council or a registered building control approver, ending with a completion certificate.
New fabric must meet Approved Document L (2021 edition incorporating 2023 amendments): walls 0.18, roof 0.15 and floor 0.18 W/m²K, windows 1.4 W/m²K or Band B. Under the simple route, new windows, doors and rooflights should not exceed 25% of the extension floor area plus any openings removed; more glass is possible with a whole-house calculation.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.
Where in Northumberland do we work?
FAQ
Questions people ask
Full plans or building notice?
Full plans for most extensions: the design is checked before work starts. A building notice suits only simple jobs.
Who inspects the work?
The council's building control team or a registered building control approver (in Scotland, the council's building standards team).
What is a completion certificate?
The document confirming the work meets the regulations. Keep it; buyers' solicitors ask for it.
Do you cover all of Northumberland?
We cover 10 towns and districts in Northumberland, including Blyth, Cramlington and Ashington.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.