Boston, Lincolnshire
Single-storey rear extension in Boston
Ground-floor space across the back of the house, usually for a kitchen, dining or family room. If you live in Boston and want to know what a single-storey rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Boston is covered from our Lincolnshire round, including PE21. A single-storey rear extension in Boston is mostly built from the garden side, so the house stays usable for most of the job.
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 single-storey rear extension cost in Boston?
In Boston, our guide for a single-storey rear extension is £1,840–£3,010 per square metre including VAT for a standard specification. East Midlands prices sit a little below our West Midlands baseline.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £22,000–£36,000 |
| 4 m wide × 5 m deep (20 m²) | £37,000–£60,000 |
| 4 m wide × 6 m deep (24 m²) | £44,000–£72,000 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission for a single-storey rear extension in Boston?
Here is how the rules in England apply to a single-storey rear extension in Boston.
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. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.
What are homes in Boston like to extend?
Boston has plenty of inter-war semis and bungalows, and single-storey rear extensions suit both.
How a single-storey rear extension in Boston comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
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.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Single-storey rear extensions near Boston
We also build single-storey rear extensions in nearby Spalding (14.1 miles) and Sleaford (16.0 miles).
- Single-storey rear extension in Spalding
- Single-storey rear extension in Sleaford
- Single-storey rear extension in Skegness
- Single-storey rear extension in Bourne
- Single-storey rear extension in Wisbech
Other work in Boston:
FAQ
Single-storey rear extension questions in Boston
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.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
Do I need a structural engineer?
Yes for the beam over the new opening and usually for the foundations. Their calculations go to building control with the drawings.
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.
Is the site visit in Boston free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
How long does a rear extension take to build in Boston?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.