St Ives, Cambridgeshire
Semi-detached rear extension in St Ives
Thinking about a semi-detached rear extension in St Ives? Single or two-storey extensions for semi-detached houses, with side access and one party wall. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
St Ives sits in Cambridgeshire, with postcode districts including PE27. In St Ives we measure the attached neighbour's extension at the survey, because it often sets the sensible depth for yours.
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 semi-detached rear extension cost in St Ives?
In St Ives, our guide for a semi-detached rear extension is £2,010–£3,290 per square metre including VAT for a standard specification. East of England prices run slightly above our West Midlands baseline; clay soils near trees are the main foundation variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £24,000–£39,500 |
| 4 m wide × 5 m deep (20 m²) | £40,500–£65,500 |
| 4 m wide × 6 m deep (24 m²) | £48,500–£79,000 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a semi-detached rear extension in St Ives?
Planning for a semi-detached rear extension in St Ives follows the English householder rules.
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.
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.
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. 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 St Ives like to extend?
Post-war semis and newer estates are typical of St Ives, and many have room for a full-width extension. Shrinkable clay is common in the East of England, so foundations near trees and hedges are designed to NHBC-style depth guidance.
How a semi-detached rear extension in St Ives comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
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.
Semi-detached rear extensions near St Ives
Close by, we work in Huntingdon, about 4.6 miles away, and Chatteris, about 10.1 miles away.
- Semi-detached rear extension in Huntingdon
- Semi-detached rear extension in Chatteris
- Semi-detached rear extension in St Neots
- Semi-detached rear extension in Cambridge
- Semi-detached rear extension in Ely
Other work in St Ives:
FAQ
Semi-detached rear extension questions in St Ives
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.
How much does a semi-detached rear extension cost in St Ives?
As a guide, £2,010–£3,290 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £24,000–£39,500 at that rate. Your written price follows the survey.
How far can I extend a semi without planning?
3 metres under permitted development in England, or up to 6 metres with prior approval, outside designated land.
Do you handle building control in St Ives?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Do I need planning permission for a rear extension in St Ives?
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.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.