What is a wraparound extension?
A wraparound extension combines a side return and a rear extension into one L-shaped addition. It gives the largest possible ground floor, often creating an open-plan kitchen, dining and living space across the whole width of the house.
How much does a wraparound extension cost in Cardiff?
In Cardiff, a wraparound extension typically costs £2,000–£2,950 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £56,000–£82,500. The guide for Cardiff reflects typical costs in Wales, roughly 8% below the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £40,000–£59,000 |
| Typical project (28 m²) | £56,000–£82,500 |
| Larger project (39 m²) | £78,000–£115,000 |
| Rate per m² | £2,000–£2,950 |
The main things that change the cost:
- Kitchen and flooring specification
- Total footprint and the amount of glazing
- Access for materials on terraced streets
- Steelwork and propping of the existing house
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a wraparound extension in Cardiff?
Before anything is built in Cardiff, we confirm which approvals apply in Wales. In Wales a wraparound extension combines side and rear elements; it can only be permitted development if each part meets the limits, so many need a householder planning application.
The Party Wall etc. Act 1996 applies in Wales, so notices must be served before work on a shared wall, on the boundary, or excavation close to a neighbour’s foundations.
We check this for your address before design work starts, so there are no surprises later.
What we handle
What we take care of:
- Design and planning application
- Removal of internal and external walls
- Walls, roof and glazing
- Building control completion
- Underfloor heating option, electrics and plastering
- Structural engineer’s design for steels and supports
How long does it take?
Build time is typically 12 to 18 weeks on site. Before that, surveys, drawings and approvals usually take 3 to 4 months, longer if the council asks for changes.
Building in Cardiff
Terraced houses in Welsh towns often have narrow plots, which suits rear and side return extensions and rear dormers.
If your home is in Cardiff or close by in Penarth, Caerphilly and Barry, a free home visit is the first step.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about wraparound extensions in Cardiff
What about the old back addition?
The side wall of the back addition is usually removed and replaced with a steel beam, so the old kitchen joins the new space.
Do you build wraparound extensions in Cardiff?
Yes. We build wraparound extensions across Cardiff, including postcodes CF10, CF11, CF14 and CF15. Every project starts with a free home visit.
How long does it take to build?
Around 12 to 18 weeks on site after approvals. Design, planning and party wall matters usually take 3 to 4 months beforehand.
Will both neighbours be affected?
Usually only the neighbour on the side return side, but rear foundations near either boundary can trigger party wall notices.
Do I need planning permission for a wraparound extension in Cardiff?
In Wales a wraparound extension combines side and rear elements; it can only be permitted development if each part meets the limits, so many need a householder planning application.
How much does a wraparound extension cost in Cardiff?
In Cardiff, a wraparound extension typically costs £2,000–£2,950 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £56,000–£82,500. Your fixed price depends on the survey and drawings.