Two-storey rear extensions in Llangefni

Before you start in Llangefni, here's what applies.

Postcode districts: LL60, LL62, LL63, LL71, LL73, LL74 and nearby districts
County / area: Gwynedd and Anglesey, Wales
Price region: Wales
Guide price: £51,500–£69,500 (£1,840–£2,480 per m²)
Approval route: It may be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor 10.5 m from the rear boundary.
Nearest towns: Menai Bridge (6.2 miles), Bangor (Gwynedd and Anglesey) (7.7 miles), Caernarfon (8.1 miles)
Distance to Bangor (Gwynedd and Anglesey): about 7.7 miles
First visit: Free, no obligation

About a two-storey rear extension

A two-storey rear extension suits you if you need more room on both floors and have a reasonably deep garden. You get one team for the whole job: a measured survey, the design, a check on whether permitted development applies, planning drawings where they are needed, structural design, building regulations approval and the build itself, carried out by vetted teams working under S&K. Every project starts with a free site visit.

Around Llangefni we also work in Menai Bridge, Bangor (Gwynedd and Anglesey) and Caernarfon, and across the rest of Gwynedd and Anglesey. Postcode districts in and near Llangefni: LL60, LL62, LL63, LL71, LL73, LL74 and nearby districts.

What it costs in Llangefni

Our guide for Wales is £1,840–£2,480 per m² including VAT. On a project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that puts a two-storey rear extension in Llangefni at roughly £51,500–£69,500. Design fees, structural calculations and approval fees are separate and listed on our prices page.

Spec	Per m²	A 4 m × 3.5 m footprint on two floors (28 m² of new floor space)
Essential	£1,690–£2,290 per m²	£47,500–£64,000
Standard	£1,840–£2,480 per m²	£51,500–£69,500
Premium	£2,210–£2,980 per m²	£62,000–£83,500

Planning and building regulations in Llangefni

In Wales, a two-storey rear extension can be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor at least 10.5 m from the rear boundary. Nothing within 2 m of a boundary can be higher than 4 m. Conservation areas and other protected areas are excluded, and a householder application costs £585.

Approval in Wales: Householder planning application: £585. Councils normally decide householder applications within 8 weeks.

Building regulations: Building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency).

Design points for Llangefni homes

Opening up the ground floor

Knocking through the old rear wall means steel beams to carry the first floor and roof above. The structural engineer sets the beam sizes, padstones and any posts, and we plan them early so the open-plan layout you want is the one that gets built.

Depth and neighbours' light

Councils check that a two-storey rear extension does not take too much light or outlook from neighbouring windows, and many use a 45-degree line drawn from the nearest habitable window. We test this at sketch stage, so the depth you are shown is one that can realistically be approved.

How we'd run your project

Visit and first ideas
One of our team visits your house in Llangefni, checks the walls, roof and drains, and sketches out options with you.
Drawings, then consent
We draw the scheme, check it against the rules in Wales, and take it through the right consent with the council.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Questions about two-storey rear extensions in Llangefni

Which postcodes do you cover around Llangefni?

We cover Llangefni (LL60, LL62, LL63, LL71, LL73, LL74 and nearby districts) and nearby places including Menai Bridge, Bangor (Gwynedd and Anglesey) and Caernarfon, plus the rest of Gwynedd and Anglesey. The first site visit is free.

Do I need planning permission for a two-storey rear extension in Llangefni?

Llangefni is in Wales, so Wales planning rules apply. It may be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor 10.5 m from the rear boundary. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

How long does a two-storey rear extension take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils normally decide householder applications within 8 weeks), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.

How much does a two-storey rear extension cost in Llangefni?

Our guide for Wales, which covers Llangefni, is £1,840–£2,480 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £51,500–£69,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Will a two-storey rear extension block my neighbour's light?

It can if it is too deep or too close to the boundary, which is why councils look closely at its effect on neighbouring windows and gardens. We test the design against light and outlook early, keep the first floor shorter or set in where needed, and use a hipped roof to reduce bulk on the boundary side.

Nearby

Other towns near Llangefni:

Other extensions in Llangefni

All two-storey extension services in Llangefni · Two-storey rear extensions across Gwynedd and Anglesey

The quickest next step is a visit. We'll look at your house in Llangefni and give you an honest view of the options.