Single-storey rear extensions for homes in Llangefni
Our design and build teams take on single-storey extensions in Llangefni, from the first measured survey through planning and building control to the finished room.
- Guide price in LlangefniFrom £19,500 inc VAT
- PlanningWelsh permitted development rules (rear up to 4 m)
- Build time10–16 weeks on site
- Postcode districtsLL77
Working in Llangefni
We cover Llangefni and the postcode districts LL77. The same team covers Bangor, Gwynedd (8 miles), Caernarfon (10 miles), Holyhead (11 miles), all within easy reach.
Just over the Clwyd border, Llandudno is about 20 miles away. Welsh housing ranges from stone terraces in the valleys to render-and-slate houses and modern estates, and the Welsh planning rules differ from England's in several places.
Planning and approvals in Llangefni
In Wales a single-storey rear extension can usually project up to 4 m beyond the rear wall without a planning application, if it is no more than 4 m high, keeps eaves to 3 m and overall height to 4 m within 2 m of a boundary, and covers no more than half the land around the original house. Wales has no larger home extension prior approval scheme.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building regulations approval is separate from planning. Wales has its own building regulations and approved documents; the council or a registered building control approver checks the plans, inspects the work and issues a completion certificate.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
Guide prices for Llangefni
Labour and material costs vary across the UK, so for Llangefni we use our Wales factor (×0.93). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Llangefni: £1,630 to £3,160 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £19,500 – £23,000 | £22,500 – £29,500 | £29,000 – £38,000 |
| 4 m × 5 m 20 m² | £32,500 – £38,500 | £38,000 – £48,500 | £48,000 – £63,500 |
| 5 m × 6 m 30 m² | £48,500 – £57,500 | £57,000 – £73,000 | £72,500 – £95,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
What is included
- Planning route checked and the right approval obtained
- Doors, windows, insulation, plastering and first fix to finish
- Walls, steel beams and the new opening into the house
- Foundations, drainage and groundworks
- Building regulations drawings and structural calculations
- Measured survey and design
From first visit to completion
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
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Your questions about a single-storey extension in Llangefni
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Llangefni, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Who do I contract with for a single-storey extension in Llangefni?
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.
Do you cover all of Llangefni?
Yes. We cover Llangefni and the surrounding parts of Gwynedd. Site visits are free and there is no obligation.
Can I stay in the house during the build?
Usually yes. Most of the work happens outside until the final weeks, when we open the rear wall. We plan that stage carefully and seal the opening with a temporary screen to keep dust down.
Will I need a steel beam?
Almost always. Opening up the rear wall to join the new room to the house needs a beam, usually steel, sized by a structural engineer. It is included in our quotes.
Book a free site visit in Llangefni
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.