Hampshire
Building Regulations for rear extensions in Hampshire
Construction drawings, structural calculations and building control through to the completion certificate. Rear extensions in Hampshire: we cover 34 towns including Southampton, Portsmouth and Basingstoke, with design, approvals and the build under one contract.
Hampshire has a mix of Victorian terraces near the centre and larger Edwardian and inter-war houses further out. Clay soils across much of the South East mean deeper foundations near trees, which we plan for at the survey.
What does it cost in Hampshire?
As a guide, £2,500–£5,500 including VAT. Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
What approvals does it need in Hampshire?
Every rear extension in England needs Building Regulations approval, whether or not planning is needed. You can use the council's building control service or a registered building control approver, by full plans (checked before work, usually within five weeks) or a building notice, and you get a completion certificate at the end.
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 Hampshire 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 Hampshire?
We cover 34 towns and districts in Hampshire, including Southampton, Portsmouth and Basingstoke.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.