Part single, part two-storey extensions in Bourne

Useful details for planning a part single, part two-storey extension in Bourne.

Postcode districts: PE10
County / area: Lincolnshire, England
Price region: East Midlands
Guide price: £70,500–£97,000 (£1,960–£2,700 per m²)
Approval route: It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission.
Nearest towns: Market Deeping (6.8 miles), Stamford (9.1 miles), Spalding (9.8 miles)
Distance to Lincoln: about 32.4 miles
First visit: Free, no obligation

About a part single, part two-storey extension

A part single, part two-storey extension is an extension where the ground floor is wider or deeper than the floor above, so only part of it rises to two storeys. It usually gives a large kitchen or living area with roof lights below and one bedroom or bathroom above. It is often a good way to add space while limiting the effect on neighbours.

Bourne sits about 32.4 miles from Lincoln. Closer to home, Market Deeping is 6.8 miles away and Stamford 9.1 miles.

What it costs in Bourne

For budgeting in Bourne, allow around £70,500–£97,000 for a part single, part two-storey extension with a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total). That's based on £1,960–£2,700 per m² including VAT for the East Midlands. Keep a contingency of around 10% for things nobody can see until the ground is opened up.

Spec	Per m²	A 6 m × 4 m ground floor and a first floor over half of it (36 m² in total)
Essential	£1,800–£2,480 per m²	£65,000–£89,500
Standard	£1,960–£2,700 per m²	£70,500–£97,000
Premium	£2,350–£3,230 per m²	£84,500–£116,500

Planning and building regulations in Bourne

In England, the extension can only be permitted development if it goes no more than 3 m beyond the original rear wall and stays at least 7 m from the rear boundary, with matching materials and roof pitch. We check the whole design against the rules, including the 50% garden coverage limit. If any part fails, or extends beyond a side wall on two floors, you need planning permission, costing £548 (or £575 for applications made from 8 December 2026).

Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.

Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.

Design points for Bourne homes

Light into the kitchen

The single-storey part is the place for roof lights or a lantern, which bring daylight deep into the plan. In England, glazing is normally limited to 25% of the new floor area plus any windows removed, unless calculations show the house still performs, so we plan the balance early.

The roof junction

Where the single-storey roof meets the two-storey wall you need a sound weathering detail, usually a lead or similar flashing, and enough height for roof lights or a lantern. We set the roof falls and the upstairs window sill heights together so they do not clash.

How we'd run your project

Free site visit
We visit your home in Bourne, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Drawings, then consent
We draw the scheme, check it against the rules in England, and take it through the right consent with the council.
Structure and building control
A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.
Build it
The new structure goes up first, then we open into the house, finish inside and get the completion certificate.

Questions about part single, part two-storey extensions in Bourne

Which postcodes do you cover around Bourne?

We cover Bourne (PE10) and nearby places including Market Deeping, Stamford and Spalding, plus the rest of Lincolnshire. The first site visit is free.

How long does a part single, part two-storey extension take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils should decide householder applications within 8 weeks of validation), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.

Who handles building regulations for a project in Bourne?

We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

Can the single-storey part be deeper than the two-storey part?

With planning permission, yes, and that is often the point of the design: the ground floor projects further into the garden while the first floor stays back from neighbours. Under permitted development, the depth limits for extensions of more than one storey can apply to the whole extension, so we confirm which route applies before drawings are finalised.

Which side should the two-storey part go on?

Usually the side furthest from the nearest neighbour's windows, so the single-storey part sits nearest them and keeps their light. Other factors are where the stairs land upstairs, which room needs the extra space and where drains run. We sketch options at the design stage and explain which is most likely to be approved.

Nearby

The same service in neighbouring towns:

Other extensions in Bourne

All two-storey extension services in Bourne · Part single, part two-storey extensions across Lincolnshire

Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Bourne.