Merthyr Tydfil, South Wales Valleys
Two-storey rear extension in Merthyr Tydfil
A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. We design, get the approvals for and build two-storey rear extensions in Merthyr Tydfil and the surrounding area, with one contract from the first survey to building control sign-off.
Merthyr Tydfil sits in the South Wales Valleys, with postcode districts including CF47 and CF48. Two-storey rear extensions suit semi-detached houses in Merthyr Tydfil 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 Merthyr Tydfil?
In Merthyr Tydfil, our guide for a two-storey rear extension is £1,670–£2,510 per square metre including VAT for a standard specification. 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 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a two-storey rear extension in Merthyr Tydfil?
Here is how the rules in Wales apply to a two-storey rear extension in Merthyr Tydfil.
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 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. In the South Wales Valleys we check the neighbours' rear windows first, because the upper floor is where most two-storey schemes win or lose planning.
How a two-storey 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.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
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.
Two-storey rear extensions near Merthyr Tydfil
Close by, we work in Aberdare, about 3.8 miles away, and Mountain Ash, about 4.4 miles away.
- Two-storey rear extension in Aberdare
- Two-storey rear extension in Mountain Ash
- Two-storey rear extension in Tredegar
- Two-storey rear extension in Treharris
- Two-storey rear extension in Rhondda
Other work in Merthyr Tydfil:
FAQ
Two-storey rear extension questions in Merthyr Tydfil
Do I need planning permission for a rear extension in Merthyr Tydfil?
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.
Do you handle building control in Merthyr Tydfil?
Yes. We apply to the council or a registered approver under the Welsh regulations and hand over the completion certificate.
Does a two-storey rear extension need planning permission?
Almost always. England and Northern Ireland allow 3 metres without an application only if at least 7 metres remains to the rear boundary; Wales and Scotland are similar or stricter.
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.
What postcode areas do you cover around Merthyr Tydfil?
Including CF47 and CF48, and the surrounding South Wales Valleys area.
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.