Ferndale · Mid Glamorgan

Two-storey rear extensions in Ferndale

We plan and build two-storey rear extensions for homeowners in Ferndale and nearby. Every project starts with a free visit and a design stage priced in writing before any work begins.

Quick reference for homeowners in Ferndale.

Postcode districts
CF43
County / area
Mid Glamorgan, 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
Rhondda (0.1 miles), Pentre (1.9 miles), Treorchy (2.5 miles)
Distance to Rhondda
about 0.1 miles
First visit
Free, no obligation

About a two-storey rear extension

A two-storey rear extension is a new two-floor addition built onto the back of your house, usually giving a larger kitchen or living space on the ground floor and one or two bedrooms or a bathroom above. Because both floors share one set of foundations and one roof, it adds a lot of floor space for the garden it uses. In some cases it can be built under permitted development, depending on where you live.

We cover Ferndale (CF43) and the places around it, including Rhondda (0.1 miles), Pentre (1.9 miles) and Treorchy.

What it costs in Ferndale

A guide price for Ferndale: around £51,500–£69,500 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). That works out at £1,840–£2,480 per m² of new floor space, including VAT at 20%. These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.

SpecPer m²A 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 Ferndale

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 Ferndale homes

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.

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.

How we'd run your project

  1. Look at the house

    We start in Ferndale 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. Finish and certify

    Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about two-storey rear extensions in Ferndale

Who handles building regulations for a project in Ferndale?

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.

Which postcodes do you cover around Ferndale?

We cover Ferndale (CF43) and nearby places including Rhondda, Pentre and Treorchy, plus the rest of Mid Glamorgan. The first site visit is free.

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

Our guide for Wales, which covers Ferndale, 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.

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

Ferndale 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.

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

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

Other extensions in Ferndale

All two-storey extension services in Ferndale · Two-storey rear extensions across Mid Glamorgan

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

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