Covering Gwynedd and Anglesey
Our side return extensions service in Gwynedd and Anglesey covers Bangor, Holyhead, Caernarfon and Llangefni and more.
Homes in Gwynedd and Anglesey
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 does a side return extension involve?
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.
- Glazed or solid roof with rooflights
- Drainage and new gully positions
- Underfloor heating ready screed if wanted
How much should I budget for a side return extension?
Guide prices for side return extensions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.
| 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 |
How is a side return extension approved in Gwynedd and Anglesey?
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. Small single-storey rear extensions can often go ahead without an application, but the limits differ from England's and there is no larger-extension prior approval route, so we check the current Welsh rules for your house before drawings are finalised.
What should I think about before starting?
- Glazed roofs need careful detailing against the neighbour’s wall.
- Many terraces sit in conservation areas, where side extensions need planning permission.
What happens after I enquire?
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- 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.
Your questions answered
Is a glazed roof too hot in summer?
Modern solar-control glass and a mix of glazed and solid roof keep it comfortable. We advise on the balance during design.
How long does a side return take?
About 10 to 14 weeks on site.
Do you work in Gwynedd and Anglesey?
Yes. Gwynedd and Anglesey is within our coverage for side return extensions, along with nearby Bangor and Holyhead.
Also covering
- Side return extensions in Bangor
- Side return extensions in Holyhead
- Side return extensions in Caernarfon
- Side return extensions in Llangefni
- Side return extensions in Pwllheli
Learn more about side return extensions, or see every project we cover in Gwynedd and Anglesey.