Beddau · Mid Glamorgan

First-floor extensions in Beddau

Thinking about a first-floor extension in Beddau? 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.

The basics for Beddau at a glance.

Postcode districts
CF38
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 (1.2 miles), Pontyclun (2.7 miles), Pontypridd (3.4 miles)
Distance to Rhondda
about 8.2 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 district CF38 in and around Beddau, along with neighbouring Llantrisant, Pontyclun and Pontypridd.

What it costs in Beddau

Expect a first-floor extension in Beddau 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. Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.

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 Beddau

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 Beddau homes

Tying into the house

The new floor and walls must line up with the existing first floor, often through a new opening in the rear wall above the old one. Floor levels, the position of upstairs windows and the existing roof all affect where the opening can go, so we survey both floors carefully.

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. Free site visit

    We visit your home in Beddau, look at the structure, access and boundaries, and talk through what you want the new rooms to do.

  2. Plans, then approval

    Measured survey, design, then the right approval route for your house. We explain each step before we take it.

  3. Technical design

    We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.

  4. Finish and certify

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

Questions about first-floor extensions in Beddau

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

Our guide for Wales, which covers Beddau, 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.

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.

Who handles building regulations for a project in Beddau?

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.

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 Beddau, including:

Other extensions in Beddau

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

Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Beddau.

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