Two-storey wraparound extensions in Treharris

The basics for Treharris at a glance.

Postcode districts: CF46
County / area: Mid Glamorgan, Wales
Price region: Wales
Guide price: £111,000–£152,000 (£1,980–£2,710 per m²)
Approval route: Usually needs planning permission, because the combined side and rear works rarely meet every permitted development test.
Nearest towns: Nelson (Mid Glamorgan) (1.2 miles), Abercynon (1.6 miles), Gelligaer (2.2 miles)
Distance to Rhondda: about 6.1 miles
First visit: Free, no obligation

About a two-storey wraparound extension

A two-storey wraparound extension is an L-shaped addition that extends both the side and the rear of your house, on two floors. It gives one of the largest gains in floor space of any extension, typically a big open-plan kitchen and living area below and two or more bedrooms or bathrooms above.

We cover postcode district CF46 in and around Treharris, along with neighbouring Nelson (Mid Glamorgan), Abercynon and Gelligaer.

What it costs in Treharris

Our guide for Wales is £1,980–£2,710 per m² including VAT. On a project with an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space), that puts a two-storey wraparound extension in Treharris at roughly £111,000–£152,000. Design fees, structural calculations and approval fees are separate and listed on our prices page.

Spec	Per m²	An L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space)
Essential	£1,820–£2,500 per m²	£102,000–£140,000
Standard	£1,980–£2,710 per m²	£111,000–£152,000
Premium	£2,370–£3,260 per m²	£133,000–£182,500

Planning and building regulations in Treharris

In Wales, a wraparound would have to pass both the side and rear tests to be permitted development: 10.5 m to the opposite side boundary, a 1 m set-back from the front and no more than 50% added width, plus the 4 m and 3 m rear depth limits and 10.5 m to the rear boundary. Many wraparounds therefore need a householder application, which 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 Treharris homes

Daylight to the middle

A deep L-shaped plan can leave the middle of the ground floor dark, because the old rear rooms are now enclosed. We use wide rear openings, a well-placed stair and, where part of the extension is single storey, roof lights, while keeping total glazing within the Part L allowance.

Two roofs that meet

A wraparound needs the side roof and rear roof to join cleanly, often with a valley or hip where they meet. Getting pitches and ridge heights right keeps rainwater moving and avoids a bulky mass at the back corner, which neighbours and planners notice.

How we'd run your project

Look at the house
We start in Treharris with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Drawings, then consent
We draw the scheme, check it against the rules in Wales, and take it through the right consent with the council.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
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 wraparound extensions in Treharris

Who handles building regulations for a project in Treharris?

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.

Do I need planning permission for a two-storey wraparound extension in Treharris?

Treharris is in Wales, so Wales planning rules apply. Usually needs planning permission, because the combined side and rear works rarely meet every permitted development test. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

How much does a two-storey wraparound extension cost in Treharris?

Our guide for Wales, which covers Treharris, is £1,980–£2,710 per m² including VAT. A typical project with an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space) comes to about £111,000–£152,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

How much floor space does a wraparound extension add?

It depends on the width of the side plot and the depth at the rear. Our guide prices are based on a typical wraparound with an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space). Yours may be larger or smaller, and the measured survey shows what your plot can take.

Can a wraparound extension be part single, part two-storey?

Yes. Many wraparounds keep the rear part single storey with roof lights over the kitchen and put the two-storey part to the side. This can reduce the effect on neighbours and the cost. We set out both options at the design stage, so you can compare floor space against price before choosing.

Nearby

Nearby towns we cover for two-storey wraparound extensions:

Other extensions in Treharris

All two-storey extension services in Treharris · Two-storey wraparound extensions across Mid Glamorgan

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