Two-storey rear extensions in Whitchurch (Cardiff and the Vale of Glamorgan)

The basics for Whitchurch (Cardiff and the Vale of Glamorgan) at a glance.

Postcode districts: CF14
County / area: Cardiff and the Vale of Glamorgan, 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: Rhiwbina (1.2 miles), Llandaff (1.3 miles), Thornhill (2.4 miles)
Distance to Cardiff: about 2.8 miles
First visit: Free, no obligation

About a two-storey rear extension

A two-storey rear extension suits you if you need more room on both floors and have a reasonably deep garden. You get one team for the whole job: a measured survey, the design, a check on whether permitted development applies, planning drawings where they are needed, structural design, building regulations approval and the build itself, carried out by vetted teams working under S&K. Every project starts with a free site visit.

Whitchurch (Cardiff and the Vale of Glamorgan) sits about 2.8 miles from Cardiff. Closer to home, Rhiwbina is 1.2 miles away and Llandaff 1.3 miles.

What it costs in Whitchurch (Cardiff and the Vale of Glamorgan)

Our guide for Wales is £1,840–£2,480 per m² including VAT. On a project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that puts a two-storey rear extension in Whitchurch (Cardiff and the Vale of Glamorgan) at roughly £51,500–£69,500. Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

Spec	Per m²	A 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 Whitchurch (Cardiff and the Vale of Glamorgan)

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 Whitchurch (Cardiff and the Vale of Glamorgan) 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.

Opening up the ground floor

Knocking through the old rear wall means steel beams to carry the first floor and roof above. The structural engineer sets the beam sizes, padstones and any posts, and we plan them early so the open-plan layout you want is the one that gets built.

How we'd run your project

Free site visit
We visit your home in Whitchurch (Cardiff and the Vale of Glamorgan), look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Drawings, then consent
We draw the scheme, check it against the rules in Wales, and take it through the right consent with the council.
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.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about two-storey rear extensions in Whitchurch (Cardiff and the Vale of Glamorgan)

Who handles building regulations for a project in Whitchurch (Cardiff and the Vale of Glamorgan)?

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 much does a two-storey rear extension cost in Whitchurch (Cardiff and the Vale of Glamorgan)?

Our guide for Wales, which covers Whitchurch (Cardiff and the Vale of Glamorgan), is £1,840–£2,480 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £51,500–£69,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

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 Whitchurch (Cardiff and the Vale of Glamorgan)?

Whitchurch (Cardiff and the Vale of Glamorgan) 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 Whitchurch (Cardiff and the Vale of Glamorgan), including:

Other extensions in Whitchurch (Cardiff and the Vale of Glamorgan)

All two-storey extension services in Whitchurch (Cardiff and the Vale of Glamorgan) · Two-storey rear extensions across Cardiff and the Vale of Glamorgan

Book a free site visit in Whitchurch (Cardiff and the Vale of Glamorgan) and we'll tell you what's possible, what approvals you need and what the design stage would cost.