Cardigan · Dyfed

First-floor extensions in Cardigan

For a first-floor extension in Cardigan, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for Dyfed.

What we'd confirm first for a project in Cardigan.

Postcode districts
SA35, SA36, SA37, SA41 and SA43
County / area
Dyfed, 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
Llangeler (12.9 miles), Fishguard (14.7 miles), Carmarthen (21.9 miles)
Distance to Llanelli
about 35 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.

We cover postcode districts SA35, SA36, SA37, SA41 and SA43 in and around Cardigan, along with neighbouring Llangeler, Fishguard and Carmarthen.

What it costs in Cardigan

Expect a first-floor extension in Cardigan to land somewhere around £23,000–£33,500 for 4 m × 3.5 m of new first-floor space (14 m²). Our Wales guide rate is £1,660–£2,390 per m², including VAT. Keep a contingency of around 10% for things nobody can see until the ground is opened up.

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 Cardigan

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 Cardigan homes

Replacing the flat roof

The existing roof usually comes off and is replaced by a new first-floor structure. The room below is exposed for a short time, so we plan temporary weatherproofing and sequence the work to keep the kitchen or living room usable for as long as possible.

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.

How we'd run your project

  1. Visit and first ideas

    One of our team visits your house in Cardigan, checks the walls, roof and drains, and sketches out options with you.

  2. Choose the approval route

    Some designs fit permitted development, most need a householder application. We decide which applies in Wales before drawing in detail.

  3. Engineer it

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

  4. Build it

    The new structure goes up first, then we open into the house, finish inside and get the completion certificate.

Questions about first-floor extensions in Cardigan

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

Our guide for Wales, which covers Cardigan, 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.

Do I need planning permission for a first-floor extension in Cardigan?

Cardigan 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.

Which postcodes do you cover around Cardigan?

We cover Cardigan (SA35, SA36, SA37, SA41 and SA43) and nearby places including Llangeler, Fishguard and Carmarthen, plus the rest of Dyfed. The first site visit is free.

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.

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.

Nearby

Close to Cardigan? We work across the area, including:

Other extensions in Cardigan

All two-storey extension services in Cardigan · First-floor extensions across Dyfed

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

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