Merseyside
Permitted development rear extensions in Merseyside
Designing to the no-application limits, with a lawful development certificate as proof. Rear extensions in Merseyside: we cover 41 towns including Liverpool, St Helens and Southport, with design, approvals and the build under one contract.
Merseyside has long runs of terraced houses with back yards and alleys, plus 1930s semis further out. Yard extensions on terraces are often single-storey and close to both boundaries.
How much does a permitted development rear extension cost in Merseyside?
In Merseyside, our guide for a permitted development rear extension is £1,790–£2,910 per square metre including VAT for a standard specification. North West prices sit below our West Midlands baseline; access on terraced streets is the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £21,500–£35,000 |
| 4 m wide × 5 m deep (20 m²) | £35,500–£58,500 |
| 4 m wide × 6 m deep (24 m²) | £43,000–£70,000 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission in Merseyside?
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.
Where in Merseyside do we work?
- Liverpool
- St Helens
- Southport
- Birkenhead
- Wallasey
- Bootle
- Bebington
- Huyton
- Kirkby
- Prescot
- Thornton-Cleveleys
- Heswall
- Maghull
- Newton-le-Willows
- Formby
- Litherland
- Garston
- Speke
- Halewood
- Norris Green
- Kirkdale
- Moreton
- Haydock
- Kensington
- Fazakerley
- Hunts Cross
- Belle Vale
- Old Swan
- Allerton
- Bromborough
- Croxteth
- Prenton
- Knotty Ash
- Wavertree
- West Derby
- Childwall
- Whiston
- Dingle
- Woolton
- Mossley Hill
- Rainhill
FAQ
Questions people ask
Is permitted development the same as planning permission?
No; it is a national grant of permission for work within set limits, so no application is needed.
Do I still need Building Regulations?
Yes, always.
Can my neighbours object?
Not to permitted development itself, though they can ask the council to check it complies. Prior approval does involve neighbour consultation.
Do you cover all of Merseyside?
We cover 41 towns and districts in Merseyside, including Liverpool, St Helens and Southport.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.