Bracknell · Berkshire

Two-storey side extensions in Bracknell

Thinking about a two-storey side extension in Bracknell? We design it, take it through the approvals it needs and build it, with one team responsible from the first visit to the final certificate.

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

Postcode districts
RG12 and RG42
County / area
Berkshire, England
Price region
South East England
Guide price
£94,500–£127,000 (£2,260–£3,030 per m²)
Approval route
Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Nearest towns
Ascot (3.3 miles), Crowthorne (3.5 miles), Wokingham (3.7 miles)
Distance to Reading
about 9.9 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.

Around Bracknell we also work in Ascot, Crowthorne and Wokingham, and across the rest of Berkshire. Postcode districts in and near Bracknell: RG12 and RG42.

What it costs in Bracknell

A guide price for Bracknell: around £94,500–£127,000 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). That works out at £2,260–£3,030 per m² of new floor space, including VAT at 20%. Professional fees for drawings and the structural engineer are listed separately on our prices page.

SpecPer m²A 3 m × 7 m footprint on two floors (42 m² of new floor space)
Essential£2,070–£2,780 per m²£87,000–£117,000
Standard£2,260–£3,030 per m²£94,500–£127,000
Premium£2,710–£3,630 per m²£113,500–£152,500

Planning and building regulations in Bracknell

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 Bracknell homes

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.

Avoiding a terracing effect

Where semi-detached houses sit close together, side extensions on neighbouring houses can join up and turn a row of pairs into a terrace. Many councils ask for a gap to the boundary at first floor to stop this, so we check local guidance before fixing the width.

How we'd run your project

  1. Visit and first ideas

    One of our team visits your house in Bracknell, checks the walls, roof and drains, and sketches out options with you.

  2. Drawings, then consent

    We draw the scheme, check it against the rules in England, and take it through the right consent with the council.

  3. Detail and price

    Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.

  4. 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 Bracknell

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.

Which postcodes do you cover around Bracknell?

We cover Bracknell (RG12 and RG42) and nearby places including Ascot, Crowthorne and Wokingham, plus the rest of Berkshire. The first site visit is free.

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

Our guide for South East England, which covers Bracknell, is £2,260–£3,030 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 £94,500–£127,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

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

Bracknell 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.

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

The same service in neighbouring towns:

Other extensions in Bracknell

All two-storey extension services in Bracknell · Two-storey side extensions across Berkshire

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