Two-storey side extensions in Bangor (Gwynedd and Anglesey)

Bangor (Gwynedd and Anglesey): the key facts for this kind of project.

Postcode districts: LL57 and LL58
County / area: Gwynedd and Anglesey, Wales
Price region: Wales
Guide price: £79,000–£106,500 (£1,890–£2,530 per m²)
Approval route: Can be permitted development in Wales if it is 10.5 m from the side boundary, set back 1 m from the front and doesn't widen the house by more than half; otherwise planning permission.
Nearest towns: Menai Bridge (1.7 miles), Bethesda (4.3 miles), Llangefni (7.7 miles)
First visit: Free, no obligation

About a two-storey side extension

A two-storey side extension is a new two-floor addition built into the space beside your house, often over a driveway or side passage. It typically adds one or two bedrooms upstairs and a utility, study or larger kitchen below, without giving up rear garden.

Around Bangor (Gwynedd and Anglesey) we also work in Menai Bridge, Bethesda and Llangefni, and across the rest of Gwynedd and Anglesey. Postcode districts in and near Bangor (Gwynedd and Anglesey): LL57 and LL58.

What it costs in Bangor (Gwynedd and Anglesey)

A guide price for Bangor (Gwynedd and Anglesey): around £79,000–£106,500 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). That works out at £1,890–£2,530 per m² of new floor space, including VAT at 20%. Design fees, structural calculations and approval fees are separate and listed on our prices page.

Spec	Per m²	A 3 m × 7 m footprint on two floors (42 m² of new floor space)
Essential	£1,740–£2,330 per m²	£73,000–£98,000
Standard	£1,890–£2,530 per m²	£79,000–£106,500
Premium	£2,260–£3,040 per m²	£95,000–£127,500

Planning and building regulations in Bangor (Gwynedd and Anglesey)

In Wales, a two-storey side extension can be permitted development if it is at least 10.5 m from the boundary opposite the side wall, set back at least 1 m from the front of the house and does not increase the house's widest width by more than 50%. If it fails any test, or the house is in a protected area, 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 Bangor (Gwynedd and Anglesey) homes

Access and services

Side extensions often cover the only route to the back garden, a gas meter, soil pipes or a drain run. We plan bin and bike access, move meters and pipes where needed and check drains early, because these items affect both cost and layout.

Set-down and set-back

Councils usually want a two-storey side extension to look subordinate to the house. Setting the front wall back from the main front and dropping the ridge slightly below the main roof helps it read as an addition, and is often expected in local design guidance.

How we'd run your project

Start at your house
We come to your home in Bangor (Gwynedd and Anglesey), measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Get it approved
Once you're happy with the design we submit it to the council for Bangor (Gwynedd and Anglesey) and deal with any questions from the planning officer.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Build it
The new structure goes up first, then we open into the house, finish inside and get the completion certificate.

Questions about two-storey side extensions in Bangor (Gwynedd and Anglesey)

How much does a two-storey side extension cost in Bangor (Gwynedd and Anglesey)?

Our guide for Wales, which covers Bangor (Gwynedd and Anglesey), is £1,890–£2,530 per m² including VAT. A typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £79,000–£106,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Do I need planning permission for a two-storey side extension in Bangor (Gwynedd and Anglesey)?

Bangor (Gwynedd and Anglesey) is in Wales, so Wales planning rules apply. Can be permitted development in Wales if it is 10.5 m from the side boundary, set back 1 m from the front and doesn't widen the house by more than half; otherwise planning permission. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

Which postcodes do you cover around Bangor (Gwynedd and Anglesey)?

We cover Bangor (Gwynedd and Anglesey) (LL57 and LL58) and nearby places including Menai Bridge, Bethesda and Llangefni, plus the rest of Gwynedd and Anglesey. The first site visit is free.

How long does a two-storey side 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.

Can I build a two-storey side extension over my driveway?

Yes, if the drive is wide enough for a useful room and the council accepts the design. You may lose off-road parking, which some councils weigh up, and the foundations need to suit the ground below. We check parking, drains and meter positions at the free site visit before any drawings are prepared.

Nearby

We also cover places near Bangor (Gwynedd and Anglesey), including:

Other extensions in Bangor (Gwynedd and Anglesey)

All two-storey extension services in Bangor (Gwynedd and Anglesey) · Two-storey side extensions across Gwynedd and Anglesey

Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Bangor (Gwynedd and Anglesey).