A single-storey extension is a new ground-floor room built onto your house, usually at the rear or side, with its own foundations, walls and roof, creating a bigger kitchen, living space or bedroom without moving home.
We arrange a single-storey extension for homeowners in Blackwood and the wider Mid Glamorgan. The job is planned, priced and managed by us and carried out by tradespeople engaged under our contract, so there is one agreement and one contact. On a typical home the work takes 10–16 weeks on site, and guide pricing in Wales is £32,000–£69,000, VAT included.
- Guide price
- £32,000–£69,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- NP12
- Planning rules
- Wales
- Local area
- Caerphilly
- Survey
- Free, with a written quote
How much does a single-storey extension cost in Blackwood?
To help you plan, we show what a single-storey extension typically costs in Blackwood instead of holding figures back for a sales call. The range is £32,000–£69,000 with VAT, using rates in Wales that are about 8% below the national guide. A free survey then fixes your actual price.
| Type of job | What it usually involves | Guide in Blackwood |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £20,000–£37,000 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £32,000–£69,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £64,000–£120,000 |
Expect these to shape the final quote:
- Floor area, shape and number of corners
- Roof type, rooflights, lanterns and the amount of glazing
- Steelwork needed to open into the existing house
- Finishes, kitchen, flooring and heating specification
What do you get?
- Groundworks, foundations and below-ground drainage
- Cavity walls built and insulated to building regulations
- Flat or pitched roof, with rooflights or a lantern if specified
- Steel beams to open into the existing house
- Electrics and plumbing by qualified trades, with certificates
- Building control inspections and completion certificate
Homes in Mid Glamorgan
The Rhondda, Cynon and Merthyr valleys are lined with stone terraces built for mining families, stepped along steep hillsides. Pontypridd, Caerphilly and Merthyr Tydfil have Victorian centres, and Bridgend has grown with large modern estates alongside interwar and post-war housing.
Valley terraces commonly need repointing, roof repairs, rendering and window replacement, and loft conversions can add useful space. Newer estate homes often take garage conversions, porches and landscaping.
Whatever era your Blackwood home dates from, we plan a single-storey extension around how it is actually built rather than a one-size-fits-all specification.
Do you need permission in Blackwood?
Homes in Blackwood come under the regulations for Wales, summarised below. We don't rely on general rules alone: we confirm the position for your address with the council before a quote goes out.
In Wales, permitted development allows many single-storey rear extensions, with depth and height limits that depend on the type of house and how close the extension comes to your boundaries. Side extensions, listed buildings, conservation areas and flats usually need planning permission.
Building Regulations in Wales apply to extensions, from foundations to insulation and fire safety. The Party Wall etc. Act 1996 applies in Wales as it does in England.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
What happens after you get in touch?
A visit to your home
We begin by looking at the job in person. During the free survey we discuss options, materials and budget for a single-storey extension, and photograph or measure anything the quote needs to reflect.
Price and scope agreed
After the survey we send a quote for a single-storey extension that fixes the price for the scope we've agreed. If you want to change materials or scope, we revise it in writing before anything is booked.
Getting ready
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Blackwood property.
The work itself
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
How we work
Frequently asked questions
Do I need an architect for an extension?
You need proper drawings for an extension, but not always a full architect service. A designer or architectural technician can produce planning and building regulations drawings, and a structural engineer provides beam and foundation calculations. If you already have drawings, we price from them. If not, we can arrange the drawings and calculations as part of the project so everything is coordinated from the start.
How much does a single-storey extension cost?
A typical single-storey rear extension of 15–25m² costs £32,000–£69,000, built to a plastered finish ready for your kitchen and decoration. As a guide, allow roughly £1,600–£2,800 per square metre plus fixed costs for groundworks, steelwork and fees. Smaller extensions cost more per square metre. The kitchen, flooring and large glazed doors are usually the biggest extras. We confirm a fixed price for the agreed specification after the survey.
Do I need planning permission in Blackwood?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Blackwood is in Wales, so Wales's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address before quoting.
What does a typical extension build look like week by week?
A typical single-storey extension follows the same order: clearing the site and digging foundations, building walls up to roof level, then fitting the roof and windows to make it weathertight. Electrics, plumbing, insulation and plastering follow. The last stage is opening into the house, laying the screed and fitting doors and finishes. Building control inspects at key stages, and we book those visits for you.
How long will a single-storey extension take?
On a typical home, allow 10–16 weeks on site. Larger projects, older buildings and extra work found once things are opened up can extend that, while simpler jobs may be shorter. Your quote includes an estimate of time on site, and your point of contact keeps you updated on the programme as the work progresses.
Nearby towns
From NP12 to the edges of Blackwood and on into Gelligaer, Risca and Caerphilly, we can arrange a site visit and a written quote for your project, planned around dates that work for you.