Merseyside
Single-storey rear extensions in Merseyside
Ground-floor space across the back of the house, usually for a kitchen, dining or family room. Across Merseyside we handle the whole rear extension: survey, drawings, the planning route, building control and the build. Towns we cover here include Liverpool, St Helens and Southport.
A single-storey rear extension in Liverpool is mostly built from the garden side, so the house stays usable for most of the job. Stone and brick terraces are common around Merseyside. Where houses back onto a ginnel or alley, deliveries can come in from the rear, which makes the build tidier.
How much does a single-storey rear extension cost in Merseyside?
A single-storey rear extension in Merseyside is priced at £1,790–£2,910 per square metre including VAT as a guide, before kitchen fit-out and fees. 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?
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is within 2 metres of a boundary.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
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
How deep can a single-storey rear extension be without planning?
In England, 3 metres on an attached house and 4 metres on a detached house under permitted development, or up to 6 and 8 metres with prior approval. Wales allows 4 metres; Scotland and Northern Ireland have their own limits.
Is a flat roof or a pitched roof better?
A warm flat roof keeps the extension low under first-floor windows and suits a roof lantern; a pitched or lean-to roof gives a vaulted ceiling. Both last for decades when built properly.
Can I stay in the house during the build?
Usually yes. The noisiest, dustiest stage, removing the back wall, is kept to the final weeks and screened off. Most families set up a temporary kitchen elsewhere in the house.
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.