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 Caernarfon?
In Caernarfon, 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. We start from a UK-wide guide and adjust it for Wales, where labour and materials are typically about 8% below average. 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 biggest cost drivers are:
- Total footprint and the amount of glazing
- Steelwork and propping of the existing house
- Party wall surveyor fees for one or both neighbours
- Access for materials on terraced streets
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a wraparound extension in Caernarfon?
The approval route for Caernarfon is set by planning law 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.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
The work we manage on a wraparound extension:
- Foundations and drainage
- Party wall notices and surveyor liaison
- Structural engineer’s design for steels and supports
- Design and planning application
- Building control completion
- Underfloor heating option, electrics and plastering
How long does it take?
Expect 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 Caernarfon
Terraced houses in Welsh towns often have narrow plots, which suits rear and side return extensions and rear dormers.
Caernarfon sits in Gwynedd, about 8 miles south-west of Bangor. We cover the whole of Caernarfon, including postcodes LL55.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about wraparound extensions in Caernarfon
Can we keep a separate living room?
Yes. Many clients keep the front room separate and open up only the back of the house.
How much does a wraparound extension cost in Caernarfon?
In Caernarfon, 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.
Do I need planning permission for a wraparound extension in Caernarfon?
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.
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.
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.
Who approves a wraparound extension in Caernarfon?
Planning matters in Caernarfon go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.