Blackwood, South Wales Valleys
Two-storey rear extension in Blackwood
We plan and build two-storey rear extensions for homeowners in Blackwood. A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. Start with a free site visit, then a written price once the design is agreed.
We cover Blackwood (NP12) as part of our South Wales Valleys work. Two-storey rear extensions suit semi-detached houses in Blackwood best, where the extra bedroom matters as much as the bigger kitchen.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a two-storey rear extension cost in Blackwood?
A two-storey rear extension in Blackwood is priced at £1,670–£2,510 per square metre including VAT as a guide, before kitchen fit-out and fees. Prices in Wales sit below our West Midlands baseline; sloping sites are the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £50,000–£75,500 |
| 4 m × 6 m footprint, two floors (48 m²) | £80,500–£120,500 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission for a two-storey rear extension in Blackwood?
Here is how the rules in Wales apply to a two-storey rear extension in Blackwood.
In Wales a rear extension of more than one storey can be permitted development if the ground floor projects no more than 4 metres and the upper floor no more than 3 metres, with at least 10.5 metres to the rear boundary. It is not permitted development in conservation areas, National Parks or National Landscapes, so many double-storey schemes need a householder application.
Conservation areas, National Parks and National Landscapes restrict permitted development in Wales, and listed buildings need listed building consent. At the first visit we measure what is there now and tell you which route fits: permitted development or a householder planning application.
What are homes in Blackwood like to extend?
Blackwood is largely terraced streets on sloping ground, where back gardens step up or down from the house. Excavation, retaining walls and drainage are priced at the survey.
How a two-storey rear extension in Blackwood comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Approvals
Permitted development check or householder planning application, then Building Regulations drawings to the Welsh Approved Documents and structural calculations, plus party wall notices where they apply.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Two-storey rear extensions near Blackwood
Neighbouring places we cover include Bargoed (1.5 miles) and Gelligaer (2.1 miles).
- Two-storey rear extension in Bargoed
- Two-storey rear extension in Gelligaer
- Two-storey rear extension in Abercarn
- Two-storey rear extension in Nelson
- Two-storey rear extension in Treharris
Other work in Blackwood:
FAQ
Two-storey rear extension questions in Blackwood
Do I need planning permission for a rear extension in Blackwood?
Often not for a single-storey rear extension of up to 4 metres under Welsh permitted development. Wales has no prior approval route for deeper extensions.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
Is two-storey cheaper per square metre than single-storey?
Usually yes, because the foundations and roof are shared across twice the floor area. The total cost is higher.
Is the site visit in Blackwood free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Do you handle building control in Blackwood?
Yes. We apply to the council or a registered approver under the Welsh regulations and hand over the completion certificate.
What postcode areas do you cover around Blackwood?
Including NP12, and the surrounding South Wales Valleys area.