Treharris, South Wales Valleys
Kitchen-diner rear extension in Treharris
An open-plan kitchen, dining and family room that opens straight onto the garden. We design, get the approvals for and build kitchen-diner rear extensions in Treharris and the surrounding area, with one contract from the first survey to building control sign-off.
Treharris sits in the South Wales Valleys, with postcode districts including CF46. For Treharris kitchens we plan the extraction route and the island drainage before the slab is poured, so nothing has to be chased in later.
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 Treharris?
In Treharris, our guide for a kitchen-diner rear extension is £1,770–£2,880 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 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 Treharris?
Whether your kitchen-diner rear extension in Treharris needs a planning application depends on its size, your house and any local restrictions.
Welsh permitted development allows a single-storey rear extension of up to 4 metres in depth and 4 metres in height, subject to boundary and garden-coverage limits. There is no larger-extension prior approval scheme in Wales.
Conservation areas, National Parks and National Landscapes restrict permitted development in Wales, and listed buildings need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Treharris like to extend?
Treharris 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 kitchen-diner rear extension in Treharris 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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
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 Treharris
Close by, we work in Nelson, about 1.2 miles away, and Gelligaer, about 2.2 miles away.
- Kitchen-diner rear extension in Nelson
- Kitchen-diner rear extension in Gelligaer
- Kitchen-diner rear extension in Mountain Ash
- Kitchen-diner rear extension in Bargoed
- Kitchen-diner rear extension in Blackwood
Other work in Treharris:
FAQ
Kitchen-diner rear extension questions in Treharris
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.
Do you handle building control in Treharris?
Yes. We apply to the council or a registered approver under the Welsh regulations and hand over the completion certificate.
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 you match the brick or stone on my Treharris house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
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.
Do I need planning permission for a rear extension in Treharris?
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.