Chepstow · Gwent

Two-storey side extensions in Chepstow

For a two-storey side extension in Chepstow, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for Gwent.

Quick reference for homeowners in Chepstow.

Postcode districts
NP16
County / area
Gwent, Wales
Price region
Wales
Guide price
£79,000–£106,500 (£1,890–£2,530 per m²)
Approval route
Can be permitted development in Wales if it is 10.5 m from the side boundary, set back 1 m from the front and doesn't widen the house by more than half; otherwise planning permission.
Nearest towns
Caldicot (5.1 miles), Undy (7.4 miles), Magor (7.9 miles)
Distance to Newport (Gwent)
about 14.3 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 Chepstow we also work in Caldicot, Undy and Magor, and across the rest of Gwent. Postcode district in and near Chepstow: NP16.

What it costs in Chepstow

For budgeting in Chepstow, allow around £79,000–£106,500 for a two-storey side extension with a 3 m × 7 m footprint on two floors (42 m² of new floor space). That's based on £1,890–£2,530 per m² including VAT for Wales. The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.

SpecPer m²A 3 m × 7 m footprint on two floors (42 m² of new floor space)
Essential£1,740–£2,330 per m²£73,000–£98,000
Standard£1,890–£2,530 per m²£79,000–£106,500
Premium£2,260–£3,040 per m²£95,000–£127,500

Planning and building regulations in Chepstow

In Wales, a two-storey side extension can be permitted development if it is at least 10.5 m from the boundary opposite the side wall, set back at least 1 m from the front of the house and does not increase the house's widest width by more than 50%. If it fails any test, or the house is in a protected area, a householder application costs £585.

Approval in Wales: Householder planning application: £585. Councils normally decide householder applications within 8 weeks.

Building regulations: Building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency).

Design points for Chepstow homes

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.

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. Measure and listen

    A visit to Chepstow to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.

  2. Drawings, then consent

    We draw the scheme, check it against the rules in Wales, 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. Finish and certify

    Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about two-storey side extensions in Chepstow

Who handles building regulations for a project in Chepstow?

We handle it as part of the project. What's needed in Wales: building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency). We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

How long does a two-storey side extension take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils normally decide householder applications within 8 weeks), 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 Chepstow?

We cover Chepstow (NP16) and nearby places including Caldicot, Undy and Magor, plus the rest of Gwent. The first site visit is free.

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

Chepstow is in Wales, so Wales planning rules apply. Can be permitted development in Wales if it is 10.5 m from the side boundary, set back 1 m from the front and doesn't widen the house by more than half; otherwise planning permission. 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

Other towns near Chepstow:

Other extensions in Chepstow

All two-storey extension services in Chepstow · Two-storey side extensions across Gwent

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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