Caerleon · Gwent

Two-storey rear extensions in Caerleon

Adding a two-storey rear extension in Caerleon gives you two new rooms stacked on one footprint. Here's how we'd approach it, what it typically costs and the rules that apply in Wales.

Quick reference for homeowners in Caerleon.

Postcode districts
NP18 and NP19
County / area
Gwent, Wales
Price region
Wales
Guide price
£51,500–£69,500 (£1,840–£2,480 per m²)
Approval route
It may be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor 10.5 m from the rear boundary.
Nearest towns
Newport (Gwent) (2.4 miles), Cwmbran (4.3 miles), Magor (5.7 miles)
Distance to Newport (Gwent)
about 2.4 miles
First visit
Free, no obligation

About a two-storey rear extension

A two-storey rear extension is a new two-floor addition built onto the back of your house, usually giving a larger kitchen or living space on the ground floor and one or two bedrooms or a bathroom above. Because both floors share one set of foundations and one roof, it adds a lot of floor space for the garden it uses. In some cases it can be built under permitted development, depending on where you live.

We cover postcode districts NP18 and NP19 in and around Caerleon, along with neighbouring Newport (Gwent), Cwmbran and Magor.

What it costs in Caerleon

A guide price for Caerleon: around £51,500–£69,500 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). That works out at £1,840–£2,480 per m² of new floor space, including VAT at 20%. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

SpecPer m²A 4 m × 3.5 m footprint on two floors (28 m² of new floor space)
Essential£1,690–£2,290 per m²£47,500–£64,000
Standard£1,840–£2,480 per m²£51,500–£69,500
Premium£2,210–£2,980 per m²£62,000–£83,500

Planning and building regulations in Caerleon

In Wales, a two-storey rear extension can be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor at least 10.5 m from the rear boundary. Nothing within 2 m of a boundary can be higher than 4 m. Conservation areas and other protected areas are excluded, and 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 Caerleon homes

Foundations and drains

Foundations for two storeys carry more load than a single storey and may need to go deeper near trees or on clay. Rear extensions often sit near drains, so we check sewer records early, as building over or near a public sewer may need the water company's agreement.

Upstairs layout and windows

Bedrooms above need a window big enough for escape or a protected route to the stairs. Side-facing upstairs windows normally have to be obscure-glazed and fixed below 1.7 m, so we put the main bedroom windows in the rear wall and use roof lights where extra daylight is needed.

How we'd run your project

  1. Start at your house

    We come to your home in Caerleon, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.

  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. Build it

    The new structure goes up first, then we open into the house, finish inside and get the completion certificate.

Questions about two-storey rear extensions in Caerleon

Who handles building regulations for a project in Caerleon?

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.

Which postcodes do you cover around Caerleon?

We cover Caerleon (NP18 and NP19) and nearby places including Newport (Gwent), Cwmbran and Magor, plus the rest of Gwent. The first site visit is free.

How long does a two-storey rear 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.

Do I need planning permission for a two-storey rear extension in Caerleon?

Caerleon is in Wales, so Wales planning rules apply. It may be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor 10.5 m from the rear boundary. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

Will a two-storey rear extension block my neighbour's light?

It can if it is too deep or too close to the boundary, which is why councils look closely at its effect on neighbouring windows and gardens. We test the design against light and outlook early, keep the first floor shorter or set in where needed, and use a hipped roof to reduce bulk on the boundary side.

Nearby

We also cover places near Caerleon, including:

Other extensions in Caerleon

All two-storey extension services in Caerleon · Two-storey rear extensions across Gwent

Tell us about your house in Caerleon and we'll call you back to arrange a free, no-obligation visit.

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