Llanelli, West Wales
Semi-detached rear extension in Llanelli
Single or two-storey extensions for semi-detached houses, with side access and one party wall. We design, get the approvals for and build rear extensions for semi-detached houses in Llanelli and the surrounding area, with one contract from the first survey to building control sign-off.
Llanelli is covered from our West Wales round, including SA15. In Llanelli 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 Llanelli?
A semi-detached rear extension in Llanelli is priced at £1,770–£2,880 per square metre including VAT as a guide, before kitchen fit-out and fees. 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 Llanelli?
Planning for a semi-detached rear extension in Llanelli follows the Welsh householder rules.
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.
Welsh rules allow a two-storey rear extension without an application only where the ground floor is no deeper than 4 metres, the upper floor no deeper than 3 metres and at least 10.5 metres remains to the rear boundary. Most homeowners still apply for householder planning permission.
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 Llanelli like to extend?
Llanelli has Victorian terraces near the centre and semis further out. Welsh permitted development allows up to 4 metres at the rear for many houses.
How a semi-detached rear extension in Llanelli 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.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Semi-detached rear extensions near Llanelli
Close by, we work in Gorseinon, about 5.2 miles away, and Swansea, about 10.3 miles away.
- Semi-detached rear extension in Gorseinon
- Semi-detached rear extension in Swansea
- Semi-detached rear extension in Ammanford
- Semi-detached rear extension in Clydach
- Semi-detached rear extension in Carmarthen
Other work in Llanelli:
FAQ
Semi-detached rear extension questions in Llanelli
How long does a rear extension take to build in Llanelli?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Can you match the brick or stone on my Llanelli house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Do I need a party wall agreement?
Usually with the attached neighbour, in England and Wales.
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 you handle building control in Llanelli?
Yes. We apply to the council or a registered approver under the Welsh regulations and hand over the completion certificate.
How much does a semi-detached rear extension cost in Llanelli?
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.