Portishead, Somerset
Two-storey rear extension in Portishead
A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. If you live in Portishead and want to know what a two-storey rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Portishead is covered from our Somerset round, including BS20. Two-storey rear extensions suit semi-detached houses in Portishead best, where the extra bedroom matters as much as the bigger kitchen.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a two-storey rear extension cost in Portishead?
In Portishead, our guide for a two-storey rear extension is £1,870–£2,810 per square metre including VAT for a standard specification. South West prices run slightly above our West Midlands baseline; natural stone to match the house is the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £56,000–£84,000 |
| 4 m × 6 m footprint, two floors (48 m²) | £90,000–£135,000 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a two-storey rear extension in Portishead?
Planning for a two-storey rear extension in Portishead follows the English householder rules.
England's rules allow a rear extension of more than one storey without an application only when it is no deeper than 3 metres and at least 7 metres from the boundary opposite the rear wall, and never on designated land. Most two-storey schemes need householder planning permission.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Portishead like to extend?
Stone-built and rendered houses are common around Portishead, so matching the walling is a design decision in its own right: natural stone, reconstituted stone or a render finish across old and new.
How a two-storey rear extension in Portishead comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Two-storey rear extensions near Portishead
Neighbouring places we cover include Nailsea (3.5 miles) and Clevedon (4.7 miles).
- Two-storey rear extension in Nailsea
- Two-storey rear extension in Clevedon
- Two-storey rear extension in Yatton
- Two-storey rear extension in Caldicot
- Two-storey rear extension in Bristol
Other work in Portishead:
FAQ
Two-storey rear extension questions in Portishead
Do I need planning permission for a rear extension in Portishead?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Can I add an en-suite upstairs?
Yes. We plan the soil pipe route early so the bathroom sits where drainage works without boxing through the room below.
Do you handle building control in Portishead?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Is the site visit in Portishead free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.