Within 200 miles of London
House extensions and kitchen extensions in Cardiff
Extensions for homes in Pontcanna, Llandaff, Cyncoed, Lisvane, Radyr and Penarth, planned, built and fitted out by the same people.
Call 07353 373753Book a survey
- One team for every trade
- Written estimate before work starts
- Gas engineers and qualified electricians
Starting prices
House extension prices: what the starting package includes
From £1,900 per m²
A simple single-storey rear extension: foundations, blockwork walls, flat roof, standard insulation, uPVC window and door, plastered and painted walls, basic sockets and lighting, and a radiator. A 15 m² extension on this specification starts from about £28,500.
Popular upgrades
Bi-fold or sliding doors, roof lights or a roof lantern, underfloor heating, a pitched roof, and a new kitchen or shower room inside the extension.
What costs extra
Drawings, structural engineer, planning and building control fees, steel beams to open up the back of the house, moving drains and party wall costs. Each one is itemised in your written quote. All starting prices include VAT.
South Wales
Extension builders in Cardiff
Plumbery is a London company. We travel to Cardiff, about 130 miles away, for complete projects rather than small repairs, and keep one project lead as your contact throughout.
Cardiff is in Wales, where permitted development rules differ from England, so we confirm with Cardiff Council whether an extension needs planning before detailed design. Building regulations in Wales are also separate from England's.
Cost and time
Budget and timescale
A single-storey rear extension typically takes around 10 to 16 weeks on site once approvals are in place. Use the house extension cost calculator for a budget with VAT, or read how we run extensions on our London house extension page.
Local know-how
Before you start in Cardiff
Cardiff is in Wales, where permitted development rules and building regulations differ from England, so we confirm with Cardiff Council whether your extension needs planning permission before detailed design.
What we do
Popular projects in Cardiff
Orangery-style room
Brick piers, a flat roof perimeter and a central lantern, suited to larger detached houses.
Wraparound extension
Side-return and rear extension combined into one L-shaped open-plan room.
Side-return extension
Filling the side passage of a terrace or semi to widen a narrow kitchen.
Glazed rear extension
Full-width glazing, slim-frame doors and a roof lantern, with the heating sized for the glass.
Our clients
Extensions across Pontcanna, Llandaff, Cyncoed, Lisvane, Radyr and Penarth
Our Cardiff work is mostly in Pontcanna, Llandaff, Cyncoed, Lisvane, Radyr and Penarth, for clients who value a finished result and a single accountable team over the cheapest quote.
Llandaff and parts of Pontcanna are conservation areas, and Penarth is in the Vale of Glamorgan, so the right council and the right design rules depend on your street.
Questions
House extension in Cardiff: your questions
Are extension rules in Cardiff the same as in England?
No. Wales has its own permitted development rules and building regulations, so we check with Cardiff Council or the Vale of Glamorgan Council before design.
Do you work in Cardiff?
Yes. We take on complete house extension projects across Cardiff, including Canton, Roath, Pontcanna, Llandaff, Whitchurch and Penarth, and in Pontcanna, Llandaff, Cyncoed, Lisvane, Radyr and Penarth.
How much does an extension cost?
It depends on size, foundations, glazing and fit-out. Our online calculator gives a budget with VAT, and the survey turns it into a written estimate.
Do you arrange drawings and building regulations?
Yes. We arrange the drawings, structural calculations, planning or a lawful development certificate and building control.
Can I stay in the house during the build?
Usually yes. The back wall stays in place while the shell is built and is opened near the end.
Why Plumbery
Qualified, insured and upfront about price
Every engineer we send is registered or qualified for the trade they work in, and you can check the details before anyone starts.
- Fully insuredEvery job is covered by our insurance.
- Rates published in advanceOur hourly rates are on the pricing page. Nothing starts until you agree the rate.
- Paperwork includedGas safety certificates and electrical records are provided on completion.
- Registered companyPlumbery Ltd, company no. 11677583, registered in England and Wales.
