Merthyr Tydfil, South Wales Valleys
Glazed rear extension in Merthyr Tydfil
For homes in Merthyr Tydfil, a glazed rear extension is often the simplest way to gain space without moving. Full-height glass, slim frames and big rooflights for the most open rear room. We take it from survey to completion certificate.
We cover Merthyr Tydfil (CF47 and CF48) as part of our South Wales Valleys work. Glass-led rear extensions in Merthyr Tydfil are planned around which way the garden faces, because that decides the glass specification.
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 Merthyr Tydfil?
For Merthyr Tydfil 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 Merthyr Tydfil?
Whether your glazed rear extension in Merthyr Tydfil needs a planning application depends on its size, your house and any local restrictions.
The Welsh Government's householder rules let many homes add a single-storey rear extension up to 4 metres deep and 4 metres high without a planning application. Deeper projects go through a householder application, because Wales has no prior approval route.
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. 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 Merthyr Tydfil like to extend?
Stone terraces along the valley floors and post-war semis higher up are typical of Merthyr Tydfil. Sloping sites are common, so floor levels and retaining walls are designed at the start.
How a glazed rear extension in Merthyr Tydfil 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.
Paperwork handled
Planning or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Glazed rear extensions near Merthyr Tydfil
From Merthyr Tydfil, the nearest places we also cover are Aberdare (3.8 miles) and Mountain Ash (4.4 miles).
- Glazed rear extension in Aberdare
- Glazed rear extension in Mountain Ash
- Glazed rear extension in Tredegar
- Glazed rear extension in Treharris
- Glazed rear extension in Rhondda
Other work in Merthyr Tydfil:
FAQ
Glazed rear extension questions in Merthyr Tydfil
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Do I need a party wall agreement?
In Wales, usually yes if the extension is on or near a shared boundary or close to a neighbour's foundations. We serve the notices.
Can I have a level threshold?
Yes, with a drainage channel outside the doors and the slab set to the patio level.
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.
Can you match the brick or stone on my Merthyr Tydfil house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
How long does a rear extension take to build in Merthyr Tydfil?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.