Two-storey side extensions in Nelson (Lancashire)

What we'd confirm first for a project in Nelson (Lancashire).

Postcode districts: BB9
County / area: Lancashire, England
Price region: North West England
Guide price: £82,000–£109,500 (£1,950–£2,610 per m²)
Approval route: Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Nearest towns: Brierfield (1.5 miles), Colne (2.1 miles), Burnley (2.7 miles)
Distance to Preston: about 21.2 miles
First visit: Free, no obligation

About a two-storey side extension

A two-storey side extension suits a detached or semi-detached house with a side garden, driveway or garage wide enough to build on. You get a design that sits comfortably on the street, a planning application or permitted development check depending on your nation, structural design, building regulations approval and the build itself. We manage the whole process, and the work is carried out by vetted teams working under S&K.

Around Nelson (Lancashire) we also work in Brierfield, Colne and Burnley, and across the rest of Lancashire. Postcode district in and near Nelson (Lancashire): BB9.

What it costs in Nelson (Lancashire)

Most of the cost of a two-storey side extension is set by its size and specification. For Nelson (Lancashire) and the rest of North West England, our guide is £1,950–£2,610 per m² including VAT, so about £82,000–£109,500 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

Spec	Per m²	A 3 m × 7 m footprint on two floors (42 m² of new floor space)
Essential	£1,790–£2,400 per m²	£75,500–£101,000
Standard	£1,950–£2,610 per m²	£82,000–£109,500
Premium	£2,340–£3,130 per m²	£98,000–£131,500

Planning and building regulations in Nelson (Lancashire)

In England, a two-storey side extension always needs householder planning permission, because permitted development only allows single-storey extensions beyond a side wall. The fee is £548 (or £575 for applications made from 8 December 2026), and councils should decide within 8 weeks of validation. Expect them to look at set-back, roof height, gaps to the boundary and the effect on neighbours.

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 Nelson (Lancashire) homes

Matching the ridge and roof

A hipped house usually needs a hipped extension roof, and a gabled house a gable. Matching the pitch, tiles, ridge detail and brick bond is what makes a side extension look original rather than added, and councils look closely at it on a front-facing addition.

Access and services

Side extensions often cover the only route to the back garden, a gas meter, soil pipes or a drain run. We plan bin and bike access, move meters and pipes where needed and check drains early, because these items affect both cost and layout.

How we'd run your project

Start at your house
We come to your home in Nelson (Lancashire), measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Price it properly
Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Questions about two-storey side extensions in Nelson (Lancashire)

How long does a two-storey side 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.

How much does a two-storey side extension cost in Nelson (Lancashire)?

Our guide for North West England, which covers Nelson (Lancashire), is £1,950–£2,610 per m² including VAT. A typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £82,000–£109,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Which postcodes do you cover around Nelson (Lancashire)?

We cover Nelson (Lancashire) (BB9) and nearby places including Brierfield, Colne and Burnley, plus the rest of Lancashire. The first site visit is free.

Who handles building regulations for a project in Nelson (Lancashire)?

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 I build a two-storey side extension over my driveway?

Yes, if the drive is wide enough for a useful room and the council accepts the design. You may lose off-road parking, which some councils weigh up, and the foundations need to suit the ground below. We check parking, drains and meter positions at the free site visit before any drawings are prepared.

Nearby

Nearby towns we cover for two-storey side extensions:

Other extensions in Nelson (Lancashire)

All two-storey extension services in Nelson (Lancashire) · Two-storey side extensions across Lancashire

Book a free site visit in Nelson (Lancashire) and we'll tell you what's possible, what approvals you need and what the design stage would cost.