Merthyr Tydfil, South Wales Valleys
Side return extension in Merthyr Tydfil
Side return extension in Merthyr Tydfil: infilling the narrow passage beside a Victorian or Edwardian back addition. We measure the house, show you what the rules allow, price it in writing and build it.
Merthyr Tydfil and its postcode districts CF47 and CF48 are part of our South Wales Valleys coverage. Side returns suit the Victorian and Edwardian terraces found across parts of the South Wales Valleys, where the kitchen sits in a narrow back addition.
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 side return extension cost in Merthyr Tydfil?
In Merthyr Tydfil, our guide for a side return extension is £2,140–£3,530 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 |
|---|---|
| 2 m wide × 6 m deep (12 m²) | £25,500–£42,500 |
| 2.5 m wide × 7 m deep (17.5 m²) | £37,500–£62,000 |
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 side return extension in Merthyr Tydfil?
Here is how the rules in Wales apply to a side return extension in Merthyr Tydfil.
In Wales a single-storey side extension can be permitted development if it is no more than 4 metres high and the house ends up no more than 50% wider than the original. Many side return infills on terraced streets, and most wraparounds, go through a householder application.
The Party Wall etc. Act 1996 also applies in Wales: two months' notice for work to a shared wall and one month for foundations dug close to a neighbour's building.
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 Merthyr Tydfil like to extend?
Merthyr Tydfil 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 side return 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.
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.
Side return extensions near Merthyr Tydfil
Close by, we work in Aberdare, about 3.8 miles away, and Mountain Ash, about 4.4 miles away.
- Side return extension in Aberdare
- Side return extension in Mountain Ash
- Side return extension in Tredegar
- Side return extension in Treharris
- Side return extension in Rhondda
Other work in Merthyr Tydfil:
FAQ
Side return extension questions in Merthyr Tydfil
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
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.
Where does the drainage go?
Side passages often carry the soil and rainwater pipes. We survey them first and reroute them under the new floor where needed.
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.
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 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.