Side return extensions across South Glamorgan
Planning a side return extension in South Glamorgan? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide priceFrom £16,500 inc VAT
- PlanningCan be permitted development; party wall notice usual
- Towns covered4
- Site visitFree, no obligation
Working in South Glamorgan
Towns we cover in South Glamorgan include Cardiff, Barry, Penarth, Cowbridge. In Wales, terraced houses with rear offshoots are common in the towns, while detached houses and bungalows dominate in rural areas.
What is included
- Party wall notice support (England and Wales)
- New boundary wall or raised party wall
- Design to keep daylight in the middle of the house
- Kitchen-ready shell or full finish
- Removal of the side wall and new steelwork
- Glazed, sloping or flat roof with rooflights
Will the council need to approve it?
In Wales a single-storey side return can fall within permitted development if it stays within the 4 m height limit and the width rules for side extensions. Conservation areas and listed buildings need consent, and the Party Wall Act applies to work on or near a shared wall.
Homes in conservation areas, national parks, National Landscapes (AONBs) and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
Building over or within 3 m of a public sewer needs the water company's consent before the foundations go in.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
How much does a side return extension cost in South Glamorgan?
These guide figures apply our Wales adjustment (×0.93) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in South Glamorgan: £1,950 to £3,530 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 1.8 m × 4.5 m 8 m² | £16,500 – £20,000 | £17,500 – £22,500 | £22,000 – £28,500 |
| 2 m × 5.5 m 11 m² | £21,000 – £26,000 | £24,500 – £31,000 | £30,500 – £39,000 |
| 2.2 m × 7 m 15 m² | £29,000 – £35,000 | £33,000 – £42,000 | £41,500 – £53,500 |
For a figure based on your own dimensions, use our guide-price tool.
How the project works
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions people ask about side return extensions
Will my neighbours in South Glamorgan be involved?
If a planning application is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
How long does a side return extension take to build in South Glamorgan?
On site, typically 10 to 14 weeks once approvals are in place. Before that, allow 6–12 weeks design and approvals.
Do I need building regulations approval in South Glamorgan?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I combine a side return with a rear extension?
Yes. That combination is a wraparound extension, which adds the most space to a terraced house.
How much does a side return extension cost?
Our guide range is about £1,950 to £3,530 per m² including VAT, so a typical 2 m × 5.5 m infill lands around £24,500 to £31,000 at standard spec in South Glamorgan, more in London.
Book a free site visit in South Glamorgan
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.