Magor · Gwent

Part single, part two-storey extensions in Magor

Adding a part single, part two-storey extension in Magor 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.

Useful details for planning a part single, part two-storey extension in Magor.

Postcode districts
NP26
County / area
Gwent, Wales
Price region
Wales
Guide price
£66,000–£91,000 (£1,840–£2,530 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
Undy (0.8 miles), Caldicot (3.2 miles), Caerleon (5.6 miles)
Distance to Newport (Gwent)
about 7.2 miles
First visit
Free, no obligation

About a part single, part two-storey extension

A part single, part two-storey extension is an extension where the ground floor is wider or deeper than the floor above, so only part of it rises to two storeys. It usually gives a large kitchen or living area with roof lights below and one bedroom or bathroom above. It is often a good way to add space while limiting the effect on neighbours.

Around Magor we also work in Undy, Caldicot and Caerleon, and across the rest of Gwent. Postcode district in and near Magor: NP26.

What it costs in Magor

Our guide for Wales is £1,840–£2,530 per m² including VAT. On a project with a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total), that puts a part single, part two-storey extension in Magor at roughly £66,000–£91,000. Professional fees for drawings and the structural engineer are listed separately on our prices page.

SpecPer m²A 6 m × 4 m ground floor and a first floor over half of it (36 m² in total)
Essential£1,690–£2,330 per m²£61,000–£84,000
Standard£1,840–£2,530 per m²£66,000–£91,000
Premium£2,210–£3,040 per m²£79,500–£109,500

Planning and building regulations in Magor

In Wales, a part two-storey rear extension can be permitted development if the first floor goes no more than 3 m and the ground floor no more than 4 m beyond the original rear wall, with the first floor at least 10.5 m from the rear boundary. Conservation areas and other protected areas are excluded. If the design falls outside these limits, 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 Magor homes

Where to put the two-storey part

The two-storey section usually works best away from the closest neighbour, with the single-storey part on that boundary side. We test a few positions against neighbours' windows, the upstairs layout and the roof shape before choosing the one to take forward.

Structure at the step

The first-floor wall above often sits over the new open-plan space, so it needs a steel beam or frame to carry it. Loads come down at different points than in a full two-storey design, and the engineer sizes the foundations to suit each part.

How we'd run your project

  1. Visit and first ideas

    One of our team visits your house in Magor, 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 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. 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 part single, part two-storey extensions in Magor

Do I need planning permission for a part single, part two-storey extension in Magor?

Magor 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.

Which postcodes do you cover around Magor?

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

How long does a part single, part two-storey 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.

Can the single-storey part be deeper than the two-storey part?

With planning permission, yes, and that is often the point of the design: the ground floor projects further into the garden while the first floor stays back from neighbours. Under permitted development, the depth limits for extensions of more than one storey can apply to the whole extension, so we confirm which route applies before drawings are finalised.

Which side should the two-storey part go on?

Usually the side furthest from the nearest neighbour's windows, so the single-storey part sits nearest them and keeps their light. Other factors are where the stairs land upstairs, which room needs the extra space and where drains run. We sketch options at the design stage and explain which is most likely to be approved.

Nearby

We also cover places near Magor, including:

Other extensions in Magor

All two-storey extension services in Magor · Part single, part two-storey extensions across Gwent

The quickest next step is a visit. We'll look at your house in Magor and give you an honest view of the options.

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