Two-storey extensions for detached houses in Blackwood

The basics for Blackwood at a glance.

Postcode districts: NP12
County / area: Gwent, 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: Bargoed (1.5 miles), Hengoed (1.6 miles), Gelligaer (2.1 miles)
Distance to Newport (Gwent): about 10.5 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.

Around Blackwood we also work in Bargoed, Hengoed and Gelligaer, and across the rest of Gwent. Postcode district in and near Blackwood: NP12.

What it costs in Blackwood

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 extension for a detached house in Blackwood at roughly £79,000–£106,500. Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.

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 Blackwood

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 Blackwood homes

Gaps to boundaries

Detached houses are often defined by the space around them. Keeping a gap to the side boundary at first floor maintains that character, helps planning and leaves access to the rear garden. In Wales the 10.5 m side distance decides whether permitted development applies.

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 Blackwood we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Design and approvals
We draw the extension and check it against the rules for Wales, then apply for planning permission or a certificate of lawfulness, whichever fits.
Structure and building control
A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.
Build
Foundations, walls, floor, roof, windows, then first and second fix. We break through into the house as late as we can.

Questions about two-storey extensions for detached houses in Blackwood

Who handles building regulations for a project in Blackwood?

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.

Do I need planning permission for a two-storey extension for a detached house in Blackwood?

Blackwood 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 Blackwood?

Our guide for Wales, which covers Blackwood, 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.

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.

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.

Nearby

We also cover places near Blackwood, including:

Other extensions in Blackwood

All two-storey extension services in Blackwood · Two-storey extensions for detached houses across Gwent

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