Llantwit Major, Cardiff and the Vale
Semi-detached rear extension in Llantwit Major
For homes in Llantwit Major, a semi-detached rear extension is often the simplest way to gain space without moving. Single or two-storey extensions for semi-detached houses, with side access and one party wall. We take it from survey to completion certificate.
Llantwit Major sits in Cardiff and the Vale, with postcode districts including CF61. In Llantwit Major we measure the attached neighbour's extension at the survey, because it often sets the sensible depth for yours.
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 semi-detached rear extension cost in Llantwit Major?
For Llantwit Major 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 |
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 semi-detached rear extension in Llantwit Major?
Planning for a semi-detached rear extension in Llantwit Major follows the Welsh householder rules.
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.
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. 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 Llantwit Major like to extend?
Older terraces near the centre and post-war semis further out are typical of Llantwit Major. Sloping sites are common in Wales, so floor levels and retaining walls are designed at the start.
How a semi-detached rear extension in Llantwit Major 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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
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.
Semi-detached rear extensions near Llantwit Major
We also build rear extensions for semi-detached houses in nearby Bridgend (7.6 miles) and Coity (8.2 miles).
- Semi-detached rear extension in Bridgend
- Semi-detached rear extension in Coity
- Semi-detached rear extension in Barry
- Semi-detached rear extension in Aberkenfig
- Semi-detached rear extension in Llantrisant
Other work in Llantwit Major:
FAQ
Semi-detached rear extension questions in Llantwit Major
What postcode areas do you cover around Llantwit Major?
Including CF61, and the surrounding Cardiff and the Vale area.
Is the site visit in Llantwit Major free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Can I match pebbledash or render?
Yes. Many semis are refinished with new render across the whole back elevation so old and new match.
Do you handle building control in Llantwit Major?
Yes. We apply to the council or a registered approver under the Welsh regulations and hand over the completion certificate.
Do I need planning permission for a rear extension in Llantwit Major?
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.
How much does a semi-detached rear extension cost in Llantwit Major?
As a guide, £1,770–£2,880 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £21,000–£34,500 at that rate. Your written price follows the survey.