Undy · Gwent

Two-storey side extensions in Undy

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

What we'd confirm first for a project in Undy.

Postcode districts
NP26
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
Magor (0.8 miles), Caldicot (2.6 miles), Caerleon (6.4 miles)
Distance to Newport (Gwent)
about 7.9 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.

Undy sits about 7.9 miles from Newport (Gwent). Closer to home, Magor is 0.8 miles away and Caldicot 2.6 miles.

What it costs in Undy

Our guide for Wales is £1,890–£2,530 per m² including VAT. On a project with a 3 m × 7 m footprint on two floors (42 m² of new floor space), that puts a two-storey side extension in Undy at roughly £79,000–£106,500. 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 Undy

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 Undy 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.

Set-down and set-back

Councils usually want a two-storey side extension to look subordinate to the house. Setting the front wall back from the main front and dropping the ridge slightly below the main roof helps it read as an addition, and is often expected in local design guidance.

How we'd run your project

  1. Measure and listen

    A visit to Undy 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. 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.

  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 Undy

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 Undy?

We cover Undy (NP26) and nearby places including Magor, Caldicot and Caerleon, plus the rest of Gwent. The first site visit is free.

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

Our guide for Wales, which covers Undy, is £1,890–£2,530 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 £79,000–£106,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Who handles building regulations for a project in Undy?

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.

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 Undy

All two-storey extension services in Undy · 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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