Pontyclun · Mid Glamorgan

First-floor extensions in Pontyclun

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

Before you start in Pontyclun, here's what applies.

Postcode districts
CF72
County / area
Mid Glamorgan, 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
Llantrisant (1.5 miles), Llanharan (2.3 miles), Beddau (2.7 miles)
Distance to Rhondda
about 9.8 miles
First visit
Free, no obligation

About a first-floor extension

A first-floor extension suits you if your house already has a single-storey extension and you need more space upstairs. You get a structural check of the existing walls and foundations, a design that ties the new floor into the house, the approvals your nation needs, building regulations approval and the build, managed by us and carried out by vetted teams working under S&K.

We cover Pontyclun (CF72) and the places around it, including Llantrisant (1.5 miles), Llanharan (2.3 miles) and Beddau.

What it costs in Pontyclun

A guide price for Pontyclun: 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%. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

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 Pontyclun

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 Pontyclun homes

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.

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. Measure and listen

    A visit to Pontyclun to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.

  2. Drawings and permission

    Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Pontyclun.

  3. Detail and price

    Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.

  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 Pontyclun

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

Our guide for Wales, which covers Pontyclun, 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.

Who handles building regulations for a project in Pontyclun?

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 long does a first-floor 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.

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

The same service in neighbouring towns:

Other extensions in Pontyclun

All two-storey extension services in Pontyclun · First-floor extensions across Mid Glamorgan

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

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