Extra bedroom and en-suite extensions in Whitchurch (Cardiff and the Vale of Glamorgan)
We plan and build extra bedroom and en-suite extensions for homeowners in Whitchurch (Cardiff and the Vale of Glamorgan) and nearby. Every project starts with a free visit and a design stage priced in writing before any work begins.
Before you start in Whitchurch (Cardiff and the Vale of Glamorgan), here's what applies.
- Postcode districts
- CF14
- County / area
- Cardiff and the Vale of Glamorgan, Wales
- Price region
- Wales
- Guide price
- £51,500–£69,500 (£1,840–£2,480 per m²), plus £5,500–£11,000 for the en-suite
- 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
- Rhiwbina (1.2 miles), Llandaff (1.3 miles), Thornhill (2.4 miles)
- Distance to Cardiff
- about 2.8 miles
- First visit
- Free, no obligation
About an extra bedroom and en-suite extension
This service suits you if you need another bedroom, or want a main bedroom with its own bathroom, without converting the loft or moving. You get a first-floor layout that connects well to your landing, an en-suite designed for plumbing and ventilation, a useful room downstairs, the approvals your nation needs and the build, managed by us and carried out by vetted teams working under S&K.
We cover Whitchurch (Cardiff and the Vale of Glamorgan) (CF14) and the places around it, including Rhiwbina (1.2 miles), Llandaff (1.3 miles) and Thornhill.
What it costs in Whitchurch (Cardiff and the Vale of Glamorgan)
Guide prices for extra bedroom and en-suite extensions in Wales are around £1,840–£2,480 per m² of new floor space, including VAT. For a typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that's roughly £51,500–£69,500 (plus £5,500–£11,000 for the en-suite). These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.
| Spec | Per m² | A 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 Whitchurch (Cardiff and the Vale of Glamorgan)
In Wales, an extra bedroom at the rear can be permitted development if the first floor goes no more than 3 m beyond the original rear wall and stays 10.5 m from the rear boundary. A two-storey side extension can also qualify if it is 10.5 m from the side boundary, set back 1 m and adds no more than 50% width. Otherwise the fee is £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 Whitchurch (Cardiff and the Vale of Glamorgan) homes
Sound and privacy
Bedrooms above a kitchen or family room benefit from an insulated floor to reduce noise. Side-facing upstairs windows usually have to be obscure-glazed, so we place the main bedroom window to the rear and the en-suite window to the side where possible.
Escape window 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 high, and the bottom no more than 1,100 mm above the floor, unless there is a protected route to the stairs. We design the windows to meet this.
How we'd run your project
Free site visit
We visit your home in Whitchurch (Cardiff and the Vale of Glamorgan), look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Engineer it
Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.
Questions about extra bedroom and en-suite extensions in Whitchurch (Cardiff and the Vale of Glamorgan)
Which postcodes do you cover around Whitchurch (Cardiff and the Vale of Glamorgan)?
We cover Whitchurch (Cardiff and the Vale of Glamorgan) (CF14) and nearby places including Rhiwbina, Llandaff and Thornhill, plus the rest of Cardiff and the Vale of Glamorgan. The first site visit is free.
Do I need planning permission for an extra bedroom and en-suite extension in Whitchurch (Cardiff and the Vale of Glamorgan)?
Whitchurch (Cardiff and the Vale of Glamorgan) 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.
Who handles building regulations for a project in Whitchurch (Cardiff and the Vale of Glamorgan)?
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 an en-suite go in a room with no window?
Yes. A shower room without a window is allowed, provided it has a mechanical extract fan to the outside that meets Part F. Many people prefer a window for daylight, but if it faces a neighbour it will usually need obscure glass. We plan the extract route early so the duct is hidden.
Does an extra bedroom add value to my house?
It usually does, though not always by the full cost. Nationwide's 2025 research found that adding a double bedroom to a two-bed house was linked to about 13% higher value, and a double bedroom and bathroom on a three-bed, one-bathroom house up to 24%. Local ceiling prices still apply.
Nearby
Other towns near Whitchurch (Cardiff and the Vale of Glamorgan):
Other extensions in Whitchurch (Cardiff and the Vale of Glamorgan)
All two-storey extension services in Whitchurch (Cardiff and the Vale of Glamorgan) · Extra bedroom and en-suite extensions across Cardiff and the Vale of Glamorgan
Want a figure first? Try our guide price tool, then book a free visit to firm it up.