Blackwood, South Wales Valleys
Glazed rear extension in Blackwood
Full-height glass, slim frames and big rooflights for the most open rear room. We design, get the approvals for and build glazed and glass-box rear extensions in Blackwood and the surrounding area, with one contract from the first survey to building control sign-off.
Blackwood sits in the South Wales Valleys, with postcode districts including NP12. A wide sliding door with one long rooflight, rather than a fully glazed roof, keeps a glass-led extension usable in summer.
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 glazed rear extension cost in Blackwood?
For Blackwood we work from the Wales rate: £2,600–£4,460 per square metre of new floor, including VAT, standard specification. Prices in Wales sit below our West Midlands baseline; sloping sites are the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £31,000–£53,500 |
| 4 m wide × 6 m deep (24 m²) | £62,500–£107,000 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a glazed rear extension in Blackwood?
Whether your glazed rear extension in Blackwood needs a planning application depends on its size, your house and any local restrictions.
In Wales a single-storey rear extension can often be permitted development if it projects no more than 4 metres beyond the rear wall and is no more than 4 metres high. Wales has no prior approval route for deeper extensions, so anything bigger needs a householder planning application.
Wales has its own Approved Document L, with targets for walls, roofs, floors and glazing similar to but not identical with England's. Heavily glazed designs are checked with a calculation.
Conservation areas, National Parks and National Landscapes restrict permitted development in Wales, and listed buildings need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
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 glazed 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.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Glazed rear extensions near Blackwood
We also build glazed and glass-box rear extensions in nearby Bargoed (1.5 miles) and Gelligaer (2.1 miles).
- Glazed rear extension in Bargoed
- Glazed rear extension in Gelligaer
- Glazed rear extension in Abercarn
- Glazed rear extension in Nelson
- Glazed rear extension in Treharris
Other work in Blackwood:
FAQ
Glazed rear extension questions in Blackwood
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.
What postcode areas do you cover around Blackwood?
Including NP12, and the surrounding South Wales Valleys area.
Can I have a level threshold?
Yes, with a drainage channel outside the doors and the slab set to the patio level.
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.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
How long does a rear extension take to build in Blackwood?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.