Side extensions across Boston
Our design and build teams take on side extensions in Boston, from the first measured survey through planning and building control to the finished room.
- Guide price in BostonFrom £20,500 inc VAT
- PlanningSingle storey can be permitted development
- Build time10–18 weeks on site
- Postcode districtsPE21
What should I budget for a side extension in Boston?
Labour and material costs vary across the UK, so for Boston we use our East Midlands factor (×0.95). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Boston: £1,660 to £3,230 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 5 m 12 m² | £20,500 – £25,500 | £23,000 – £30,500 | £29,500 – £39,000 |
| 3 m × 6 m 18 m² | £29,500 – £36,000 | £35,000 – £45,500 | £44,000 – £58,500 |
| 3 m × 8 m 24 m² | £39,500 – £48,000 | £46,500 – £60,500 | £59,000 – £78,000 |
Try the guide-price tool to see a range for your own size and finish.
When a side extension makes sense
- Houses where the rear garden is small
- Homes needing a utility, study or ground-floor bedroom
- Detached and semi-detached houses with side land
Covering Boston
Postcode districts we cover around Boston include PE21. Neighbouring towns we cover include Spalding (14 miles), Skegness (19 miles), Grantham (26 miles), Lincoln (27 miles).
The East Midlands has plenty of inter-war and post-war semis and detached houses with room to extend, alongside Victorian terraces in the towns.
Will the council need to approve it?
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Boston
Who do I contract with for a side extension in Boston?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
How long does a side extension take to build in Boston?
On site, typically 10 to 18 weeks once approvals are in place. Before that, allow 6–14 weeks design and approvals.
Do you cover all of Boston?
Yes. We cover Boston and the surrounding parts of Lincolnshire. Site visits are free and there is no obligation.
How close to the boundary can I build?
It depends on height. In England, within 2 m of a boundary the eaves must not exceed 3 m under permitted development. Building on the boundary is possible but brings party wall and maintenance access issues we plan for.
How much does a side extension cost?
Our guide range is about £1,660 to £3,230 per m² including VAT, depending on specification, so a standard 18 m² single-storey side extension lands around £35,000 to £45,500 in Boston.
Book a free site visit in Boston
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.