Two-storey side extensions in Llantrisant
Want to stay in Llantrisant but need more space? A two-storey side extension adds floor area on two levels without giving up much garden. Here's what's involved.
What we'd confirm first for a project in Llantrisant.
- Postcode districts
- CF72
- County / area
- Mid Glamorgan, Wales
- Price region
- Wales
- Guide price
- £79,000–£106,500 (£1,890–£2,530 per m²)
- Approval route
- Can be permitted development in Wales if it is 10.5 m from the side boundary, set back 1 m from the front and doesn't widen the house by more than half; otherwise planning permission.
- Nearest towns
- Beddau (1.2 miles), Pontyclun (1.5 miles), Llanharan (2.8 miles)
- Distance to Rhondda
- about 8.8 miles
- First visit
- Free, no obligation
About a two-storey side extension
A two-storey side extension suits a detached or semi-detached house with a side garden, driveway or garage wide enough to build on. You get a design that sits comfortably on the street, a planning application or permitted development check depending on your nation, structural design, building regulations approval and the build itself. We manage the whole process, and the work is carried out by vetted teams working under S&K.
We cover postcode district CF72 in and around Llantrisant, along with neighbouring Beddau, Pontyclun and Llanharan.
What it costs in Llantrisant
Guide prices for two-storey side extensions in Wales are around £1,890–£2,530 per m² of new floor space, including VAT. For a typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space), that's roughly £79,000–£106,500. Professional fees for drawings and the structural engineer are listed separately on our prices page.
| Spec | Per m² | A 3 m × 7 m footprint on two floors (42 m² of new floor space) |
|---|---|---|
| Essential | £1,740–£2,330 per m² | £73,000–£98,000 |
| Standard | £1,890–£2,530 per m² | £79,000–£106,500 |
| Premium | £2,260–£3,040 per m² | £95,000–£127,500 |
Planning and building regulations in Llantrisant
In Wales, a two-storey side extension can be permitted development if it is at least 10.5 m from the boundary opposite the side wall, set back at least 1 m from the front of the house and does not increase the house's widest width by more than 50%. If it fails any test, or the house is in a protected area, 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 Llantrisant homes
Access and services
Side extensions often cover the only route to the back garden, a gas meter, soil pipes or a drain run. We plan bin and bike access, move meters and pipes where needed and check drains early, because these items affect both cost and layout.
Set-down and set-back
Councils usually want a two-storey side extension to look subordinate to the house. Setting the front wall back from the main front and dropping the ridge slightly below the main roof helps it read as an addition, and is often expected in local design guidance.
How we'd run your project
Measure and listen
A visit to Llantrisant to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Design and approvals
We draw the extension and check it against the rules for Wales, then apply for planning permission or a certificate of lawfulness, whichever fits.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.
Questions about two-storey side extensions in Llantrisant
How long does a two-storey side 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.
How much does a two-storey side extension cost in Llantrisant?
Our guide for Wales, which covers Llantrisant, is £1,890–£2,530 per m² including VAT. A typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £79,000–£106,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Which postcodes do you cover around Llantrisant?
We cover Llantrisant (CF72) and nearby places including Beddau, Pontyclun and Llanharan, plus the rest of Mid Glamorgan. The first site visit is free.
Who handles building regulations for a project in Llantrisant?
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.
Can I build a two-storey side extension over my driveway?
Yes, if the drive is wide enough for a useful room and the council accepts the design. You may lose off-road parking, which some councils weigh up, and the foundations need to suit the ground below. We check parking, drains and meter positions at the free site visit before any drawings are prepared.
Nearby
Other towns near Llantrisant:
Other extensions in Llantrisant
- Rear
- Wraparound
- Part two-storey
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Llantrisant · Two-storey side 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 Llantrisant.