Two-storey extensions for detached houses in Whitchurch (Cardiff and the Vale of Glamorgan)

What we'd confirm first for a project in Whitchurch (Cardiff and the Vale of Glamorgan).

Postcode districts: CF14
County / area: Cardiff and the Vale of Glamorgan, Wales
Price region: Wales
Guide price: £79,000–£106,500 (£1,890–£2,530 per m²)
Approval route: Depends on position: rear (3 m first floor, 10.5 m to the boundary) and some side extensions (10.5 m, 1 m set-back) can be permitted development in Wales.
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 extension for a detached house

This service suits you if you own a detached house and want a substantial amount of extra space, whether a side extension over a drive, a rear extension into the garden or a wraparound. You get a survey of the whole plot, options that compare layouts and costs, the approvals your nation needs, structural design and the build, carried out by vetted teams working under S&K.

We cover postcode district CF14 in and around Whitchurch (Cardiff and the Vale of Glamorgan), along with neighbouring Rhiwbina, Llandaff and Thornhill.

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

For budgeting in Whitchurch (Cardiff and the Vale of Glamorgan), allow around £79,000–£106,500 for a two-storey extension for a detached house 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. These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.

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

In Wales, detached houses are more likely to meet the permitted development tests for a two-storey side extension: 10.5 m to the boundary opposite the side wall, a 1 m set-back from the front and no more than 50% added width. Rear permitted development allows 4 m on the ground floor and 3 m on the first floor. Otherwise the fee is £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

Larger spans and steelwork

Bigger extensions often mean wider openings and longer spans, which need more steel and sometimes a steel frame. The engineer designs these early, because the size of the steel affects ceiling heights, floor depths and the cost.

Keeping it subordinate

Large detached houses can take a large extension, but councils still expect it to look secondary to the main house. A lower ridge, a modest set-back at the front and matching materials keep the proportions right, even on a wide plot.

How we'd run your project

Understand the brief
At your home in Whitchurch (Cardiff and the Vale of Glamorgan) we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Whitchurch (Cardiff and the Vale of Glamorgan).
Structure and building control
A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

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

Do I need planning permission for a two-storey extension for a detached house in Whitchurch (Cardiff and the Vale of Glamorgan)?

Whitchurch (Cardiff and the Vale of Glamorgan) is in Wales, so Wales planning rules apply. Depends on position: rear (3 m first floor, 10.5 m to the boundary) and some side extensions (10.5 m, 1 m set-back) can be permitted development in Wales. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

How much does a two-storey extension for a detached house cost in Whitchurch (Cardiff and the Vale of Glamorgan)?

Our guide for Wales, which covers Whitchurch (Cardiff and the Vale of Glamorgan), 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 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.

Can I extend a detached house on both sides?

Sometimes. With planning permission, a council may accept extensions on both sides if the house stays well proportioned and keeps gaps to the boundaries. It is more common to extend on one side and the rear, or with a wraparound. We look at the plot as a whole before suggesting more than one extension.

Is a detached house extension a better investment than moving?

It often costs less than the gap between your house and a larger one nearby, once property tax, legal fees and removal costs are counted, but that depends on your area. Extending also has limits: every street has a ceiling price. We give you build costs so you can compare them with local asking prices.

Nearby

Other towns near Whitchurch (Cardiff and the Vale of Glamorgan):

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 extensions for detached houses across Cardiff and the Vale of Glamorgan

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