Cardiff, Cardiff and the Vale
Wraparound extension in Cardiff
An L-shaped extension that fills the side return and runs across the back. If you live in Cardiff and want to know what a wraparound extension would cost and whether it needs planning, start with the online guide price or a free site visit.
We cover Cardiff (CF3, CF5, CF11 and CF14) as part of our Cardiff and the Vale work. Wraparound projects around Cardiff often involve two neighbours, so we start the party wall conversations early.
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 wraparound extension cost in Cardiff?
Guide prices for a wraparound extension in Cardiff start from our Wales rate of £2,050–£3,350 per square metre, including VAT. Prices in Wales sit below our West Midlands baseline; sloping sites are the main variable.
| Size | Guide price inc VAT |
|---|---|
| L-shaped, about 22 m² of new floor | £45,000–£73,500 |
| L-shaped, about 30 m² of new floor | £61,500–£100,500 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a wraparound extension in Cardiff?
The planning route for a wraparound extension in Cardiff is set by Wales's householder rules and your council.
Welsh side-extension rules limit a single-storey side addition to 4 metres high and a 50% increase in the width of the original house, with tighter limits in conservation areas. Wraparounds usually need a planning application.
In Wales, as in England, the Party Wall etc. Act 1996 requires notice to neighbours before work to a shared wall or excavation near their foundations.
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 Cardiff like to extend?
Cardiff 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 wraparound extension in Cardiff 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.
Wraparound extensions near Cardiff
We also build wraparound extensions in nearby Whitchurch (2.8 miles) and Penarth (2.9 miles).
- Wraparound extension in Whitchurch
- Wraparound extension in Penarth
- Wraparound extension in Rhiwbina
- Wraparound extension in Caerphilly
- Wraparound extension in Barry
Other work in Cardiff:
FAQ
Wraparound extension questions in Cardiff
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.
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.
How long does a wraparound take?
Usually 14 to 20 weeks on site, longer than a plain rear extension because of the steelwork.
Is the site visit in Cardiff free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
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.