Side return extensions across Caernarfon
We design and build side return extensions for houses in Caernarfon, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in CaernarfonFrom £16,500 inc VAT
- PlanningCan be permitted development; party wall notice usual
- Build time10–14 weeks on site
- Postcode districtsLL55
Working in Caernarfon
Across LL55, we can visit, measure and advise. The same team covers Bangor, Gwynedd (7 miles), Llangefni (10 miles), Holyhead (19 miles), all within easy reach.
For homes towards Clwyd, Llandudno is around 20 miles away. In Wales, terraced houses with rear offshoots are common in the towns, while detached houses and bungalows dominate in rural areas.
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
The Party Wall etc. Act 1996 applies in Wales as in England: notice must be served before work to a shared wall, building on the boundary, or excavating close to a neighbour's foundations.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
What should I budget for a side return extension in Caernarfon?
Labour and material costs vary across the UK, so for Caernarfon we use our Wales factor (×0.93). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Caernarfon: £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.
When a side return extension makes sense
- Homes where the garden is too small to lose much depth
- Victorian and Edwardian terraces with a rear outrigger
- Narrow galley kitchens
Light is the design problem. A side return can make the middle of the house darker if the roof is solid, so we model the daylight and usually recommend a glazed slope or a run of rooflights along the boundary edge.
Our process, step by step
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Your questions about a side return extension in Caernarfon
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Caernarfon, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Will my neighbours in Caernarfon 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.
Who do I contract with for a side return extension in Caernarfon?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
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 Caernarfon, more in London.
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.
Book a free site visit in Caernarfon
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.