Wallingford · Oxfordshire

Two-storey side extensions in Wallingford

Homes in Wallingford with a bit of space to the side or rear can often take a two-storey side extension. We'll tell you honestly whether yours can, and what approvals it needs.

Quick reference for homeowners in Wallingford.

Postcode districts
OX10, OX49 and RG8
County / area
Oxfordshire, 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
Didcot (5.1 miles), Abingdon (8.4 miles), Cowley (9.8 miles)
Distance to Oxford
about 11.9 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.

Wallingford sits about 11.9 miles from Oxford. Closer to home, Didcot is 5.1 miles away and Abingdon 8.4 miles.

What it costs in Wallingford

Expect a two-storey side extension in Wallingford to land somewhere around £94,500–£127,000 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Our South East England guide rate is £2,260–£3,030 per m², including VAT. Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.

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 Wallingford

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 Wallingford 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.

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.

How we'd run your project

  1. Free site visit

    We visit your home in Wallingford, look at the structure, access and boundaries, and talk through what you want the new rooms to do.

  2. Drawings and permission

    Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Wallingford.

  3. Engineer it

    Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.

  4. Build and sign-off

    Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.

Questions about two-storey side extensions in Wallingford

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

Wallingford 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.

Which postcodes do you cover around Wallingford?

We cover Wallingford (OX10, OX49 and RG8) and nearby places including Didcot, Abingdon and Cowley, plus the rest of Oxfordshire. The first site visit is free.

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 Wallingford?

Our guide for South East England, which covers Wallingford, 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.

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

Other towns near Wallingford:

Other extensions in Wallingford

All two-storey extension services in Wallingford · Two-storey side extensions across Oxfordshire

Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.

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