Two-storey side extensions in Bethesda

The basics for Bethesda at a glance.

Postcode districts: LL57
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: Bangor (Gwynedd and Anglesey) (4.3 miles), Menai Bridge (5.6 miles), Caernarfon (9.2 miles)
Distance to Bangor (Gwynedd and Anglesey): about 4.3 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.

We cover Bethesda (LL57) and the places around it, including Bangor (Gwynedd and Anglesey) (4.3 miles), Menai Bridge (5.6 miles) and Caernarfon.

What it costs in Bethesda

In Wales, which includes Bethesda, we'd expect a two-storey side extension to cost around £79,000–£106,500 for a 3 m × 7 m footprint on two floors (42 m² of new floor space), or £1,890–£2,530 per m² including VAT. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

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 Bethesda

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 Bethesda 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 Bethesda, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Structure and building control
A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.
Build
Foundations, walls, floor, roof, windows, then first and second fix. We break through into the house as late as we can.

Questions about two-storey side extensions in Bethesda

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.

Do I need planning permission for a two-storey side extension in Bethesda?

Bethesda 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.

How much does a two-storey side extension cost in Bethesda?

Our guide for Wales, which covers Bethesda, 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.

Which postcodes do you cover around Bethesda?

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

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 Bethesda, including:

Other extensions in Bethesda

All two-storey extension services in Bethesda · Two-storey side extensions across Gwynedd and Anglesey

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