Mountain Ash, South Wales Valleys
Kitchen-diner rear extension in Mountain Ash
For homes in Mountain Ash, a kitchen-diner rear extension is often the simplest way to gain space without moving. An open-plan kitchen, dining and family room that opens straight onto the garden. We take it from survey to completion certificate.
Mountain Ash is covered from our South Wales Valleys round, including CF43 and CF45. We usually keep the working kitchen where the old one was and put the dining table in the new space by the doors, which suits most Mountain Ash homes.
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 kitchen-diner rear extension cost in Mountain Ash?
For Mountain Ash we work from the Wales rate: £1,770–£2,880 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) | £21,000–£34,500 |
| 4 m wide × 5 m deep (20 m²) | £35,500–£57,500 |
| 4 m wide × 6 m deep (24 m²) | £42,500–£69,000 |
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 kitchen-diner rear extension in Mountain Ash?
Here is how the rules in Wales apply to a kitchen-diner rear extension in Mountain Ash.
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.
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 Mountain Ash like to extend?
Stone terraces along the valley floors and post-war semis higher up are typical of Mountain Ash. Sloping sites are common, so floor levels and retaining walls are designed at the start.
How a kitchen-diner rear extension in Mountain Ash comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
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.
Kitchen-diner rear extensions near Mountain Ash
We also build kitchen-diner rear extensions in nearby Treharris (3.4 miles) and Rhondda (3.4 miles).
- Kitchen-diner rear extension in Treharris
- Kitchen-diner rear extension in Rhondda
- Kitchen-diner rear extension in Aberdare
- Kitchen-diner rear extension in Merthyr Tydfil
- Kitchen-diner rear extension in Nelson
Other work in Mountain Ash:
FAQ
Kitchen-diner rear extension questions in Mountain Ash
What postcode areas do you cover around Mountain Ash?
Including CF43 and CF45, 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.
Should the sink face the garden?
If the plan allows, an island sink or hob facing the glass is a common choice. It needs a floor-level drain run, which is easy to lay in a new slab.
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.
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.
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.