Amlwch · Gwynedd and Anglesey

First-floor extensions in Amlwch

Thinking about a first-floor extension in Amlwch? We design it, take it through the approvals it needs and build it, with one team responsible from the first visit to the final certificate.

Quick reference for homeowners in Amlwch.

Postcode districts
LL66, LL67, LL68, LL69, LL70 and LL72
County / area
Gwynedd and Anglesey, Wales
Price region
Wales
Guide price
£23,000–£33,500 (£1,660–£2,390 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
Llangefni (10.8 miles), Holyhead (13.8 miles), Menai Bridge (14.6 miles)
Distance to Bangor (Gwynedd and Anglesey)
about 15.5 miles
First visit
Free, no obligation

About a first-floor extension

A first-floor extension is a new upstairs room built on top of an existing single-storey part of your house, such as a rear kitchen extension, a utility or a side annexe. It adds a bedroom, bathroom or study without enlarging the footprint. Whether it works depends mainly on whether the walls and foundations below can carry the extra load.

Amlwch sits about 15.5 miles from Bangor (Gwynedd and Anglesey). Closer to home, Llangefni is 10.8 miles away and Holyhead 13.8 miles.

What it costs in Amlwch

A guide price for Amlwch: around £23,000–£33,500 for 4 m × 3.5 m of new first-floor space (14 m²). That works out at £1,660–£2,390 per m² of new floor space, including VAT at 20%. Professional fees for drawings and the structural engineer are listed separately on our prices page.

SpecPer m²4 m × 3.5 m of new first-floor space (14 m²)
Essential£1,520–£2,200 per m²£21,500–£31,000
Standard£1,660–£2,390 per m²£23,000–£33,500
Premium£1,990–£2,870 per m²£28,000–£40,000

Planning and building regulations in Amlwch

In Wales, a first floor over a rear extension can be permitted development if it goes no more than 3 m beyond the original rear wall and stays at least 10.5 m from the rear boundary, with the ground floor within 4 m. Over a side extension, the 10.5 m, 1 m set-back and 50% width tests apply. Otherwise 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 Amlwch homes

Escape and fire safety

A new first-floor bedroom needs an escape window with a clear opening of at least 0.33 m², at least 450 mm wide and 450 mm high, with the bottom no more than 1,100 mm above the floor, unless there is a protected route to the stairs.

Can the existing structure take it?

Many single-storey extensions were built with foundations, walls and lintels sized for one storey. We find out what is there with trial holes and, where available, the original building control drawings. The engineer then decides whether to reuse, strengthen or rebuild parts of the structure.

How we'd run your project

  1. Look at the house

    We start in Amlwch with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.

  2. Drawings, then consent

    We draw the scheme, check it against the rules in Wales, and take it through the right consent with the council.

  3. Engineer it

    Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.

  4. Build and sign-off

    Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.

Questions about first-floor extensions in Amlwch

Who handles building regulations for a project in Amlwch?

We handle it as part of the project. What's needed in Wales: building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency). We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

How much does a first-floor extension cost in Amlwch?

Our guide for Wales, which covers Amlwch, is £1,660–£2,390 per m² including VAT. A typical project with 4 m × 3.5 m of new first-floor space (14 m²) comes to about £23,000–£33,500. 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 Amlwch?

We cover Amlwch (LL66, LL67, LL68, LL69, LL70 and LL72) and nearby places including Llangefni, Holyhead and Menai Bridge, plus the rest of Gwynedd and Anglesey. The first site visit is free.

What happens to the room below while the first floor is built?

The old roof is removed, so the room below is exposed for a short period. We fit temporary weather protection, plan the work so the roof comes off only when the new structure is ready, and agree with you which rooms will be out of use and for roughly how long.

Can I build on top of my existing single-storey extension?

Often yes, but only after the structure has been checked. Foundations, walls and lintels built for one storey may not carry two. We dig trial holes, look for the original building control approval and ask the structural engineer to confirm what can stay, what needs strengthening and what must be rebuilt.

Nearby

We also cover places near Amlwch, including:

Other extensions in Amlwch

All two-storey extension services in Amlwch · First-floor extensions across Gwynedd and Anglesey

Tell us about your house in Amlwch and we'll call you back to arrange a free, no-obligation visit.

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