house-extension.uk

Bedroom extensions for homes in Boston

Our design and build teams take on bedroom extensions in Boston, from the first measured survey through planning and building control to the finished room.

  • Guide price in BostonFrom £24,500 inc VAT
  • PlanningUsually a householder application
  • Build time14–22 weeks on site
  • Postcode districtsPE21
Bedroom in an extension with a roof window and an en-suite shower room

Planning rules that apply in Boston

In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.

Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.

Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.

Applications are decided by the local planning authority (your district, borough or unitary council).

Local to Boston

Across PE21, we can visit, measure and advise. Nearby, we also take on projects in Spalding (14 miles), Skegness (19 miles), Grantham (26 miles), Lincoln (27 miles).

For homes towards Cambridgeshire, Wisbech is around 23 miles away. 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.

Who a bedroom extension suits

  • Growing families
  • Homeowners who want an en-suite master bedroom
  • Multi-generational households

New bedrooms on an upper floor need an escape window or a protected route to the outside under the building regulations. We design the window sizes and stair route to meet that from the outset.

What should I budget for a bedroom extension in Boston?

Prices below are for Boston, using the East Midlands factor of ×0.95. They are guide ranges including VAT for the build only, not a quote.

Typical rates in Boston: £1,520 to £3,040 per m² including VAT, depending on specification.

SizeEssentialStandardPremium
One bedroom
12 m²
£24,500 – £30,500£24,500 – £32,000£27,000 – £36,500
Bedroom and en-suite
18 m²
£27,000 – £33,500£32,000 – £42,000£41,000 – £55,000
Two rooms
30 m²
£45,500 – £56,000£54,000 – £70,000£68,000 – £91,500

For a figure based on your own dimensions, use our guide-price tool.

From first visit to completion

Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.

  1. Free site visit

    First, a site visit: we look at the house, garden, access and drains and listen to what you need.

  2. Design and approvals

    Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.

  3. Fixed written price

    You receive a written, itemised price and programme. Nothing starts until you are happy with it.

  4. Build and sign-off

    We build it with one project manager, book the building control inspections and hand over the completion certificate.

Common questions in Boston

Can I see a price before committing to anything?

Yes. The guide prices on this page are adjusted for Boston, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.

Who do I contract with for a bedroom 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 bedroom extension take to build in Boston?

On site, typically 14 to 22 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.

Does an en-suite need a window?

No, but it needs mechanical extraction that meets the building regulations. We design the duct route at the drawing stage.

How much does a bedroom extension cost?

Our guide range is about £1,520 to £3,040 per m² including VAT. A bedroom with an en-suite of about 18 m² is typically £32,000 to £42,000 at standard spec, depending on whether it is part of a larger two-storey build.

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 .

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