Two-storey side extensions in Accrington

Before you start in Accrington, here's what applies.

Postcode districts: BB5
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: Great Harwood (3 miles), Haslingden (3.8 miles), Padiham (3.8 miles)
Distance to Preston: about 14.1 miles
First visit: Free, no obligation

About a two-storey side extension

A two-storey side extension is a new two-floor addition built into the space beside your house, often over a driveway or side passage. It typically adds one or two bedrooms upstairs and a utility, study or larger kitchen below, without giving up rear garden.

We cover Accrington (BB5) and the places around it, including Great Harwood (3.0 miles), Haslingden (3.8 miles) and Padiham.

What it costs in Accrington

In North West England, which includes Accrington, we'd expect a two-storey side extension to cost around £82,000–£109,500 for a 3 m × 7 m footprint on two floors (42 m² of new floor space), or £1,950–£2,610 per m² including VAT. 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 Accrington

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 Accrington 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.

Side windows, boundaries and gutters

Upstairs windows in the side wall face the neighbour, so they are usually obscure-glazed and fixed, or left out. Building close to the boundary also raises questions about foundations, overhanging gutters and access for maintenance, so we design the eaves and gutter to stay within your land.

How we'd run your project

Free site visit
We visit your home in Accrington, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Design and approvals
We draw the extension and check it against the rules for England, then apply for planning permission or a certificate of lawfulness, whichever fits.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
Build
Foundations, walls, floor, roof, windows, then first and second fix. We break through into the house as late as we can.

Questions about two-storey side extensions in Accrington

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.

Do I need planning permission for a two-storey side extension in Accrington?

Accrington is in England, so England planning rules apply. Planning permission is needed: in England, permitted development only allows single-storey extensions to the side. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

How much does a two-storey side extension cost in Accrington?

Our guide for North West England, which covers Accrington, 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 Accrington?

We cover Accrington (BB5) and nearby places including Great Harwood, Haslingden and Padiham, plus the rest of Lancashire. The first site visit is free.

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

Close to Accrington? We work across the area, including:

Other extensions in Accrington

All two-storey extension services in Accrington · Two-storey side extensions across Lancashire

The quickest next step is a visit. We'll look at your house in Accrington and give you an honest view of the options.