Covering Penarth
Our coverage around Penarth (CF64) also includes Cardiff (3 miles to the north) and Whitchurch.
Homes in South Glamorgan
Welsh homes include long terraces built into hillsides, stone cottages and modern estates, and sloping sites often shape how and where an extension can go.
What do you get with a side return extension?
Side returns are small in area but heavy in detail: party walls, a glazed roof, and steelwork to take out the original back wall. We design the roof for light and drainage, agree the party wall process early, and keep the work tidy because access is often through the house.
- Party wall notices and surveyor liaison
- Drainage and new gully positions
- Underfloor heating ready screed if wanted
What is the guide price for a side return extension in Penarth?
Use these ranges to budget for side return extensions; the survey turns them into a fixed price for the agreed specification.
| Side return extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £3,350 to £3,700 per m² |
| Good specification | £3,700 to £4,150 per m² |
| High specification | £4,150 to £4,550 per m² |
What approvals does a side return extension need in Wales?
Welsh projects need planning clearance from the council under Welsh rules, building regulations approval under the Welsh approved documents, and party wall notices where the work affects a neighbour’s wall or foundations.
Wales has its own permitted development rules, set by the Welsh Government.
What should I think about before starting?
- Access is often through the house, so we plan deliveries and protect floors.
- Many terraces sit in conservation areas, where side extensions need planning permission.
What are the steps?
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
What people ask before starting
How much does a side return extension cost?
Usually about £3,350 to £4,550 per square metre including VAT, which works out at around £35,000 to £55,000 for a typical side return before the kitchen.
Will I need a party wall agreement?
Most likely, because the new wall usually sits on or near the boundary. We serve the notices and work with your neighbour’s surveyor if one is appointed.
Who deals with the council for a project in Penarth?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Also covering
- Side return extensions in Cardiff
- Side return extensions in Whitchurch
- Side return extensions in Barry
- Side return extensions in Caerphilly
Learn more about side return extensions, or see every project we cover in Penarth.

