House extensions in Caerphilly
Every type of house extension in Caerphilly, from single-storey kitchen extensions to two-storey additions, side returns and orangeries. We design, handle the approvals and build.
- Postcode districtsCF83
- Price regionWales (×0.93)
- Planning rulesWales
- Site visitFree, no obligation
Popular extension prices in Caerphilly
Prices on this page use our Wales factor of ×0.93, include VAT at 20% and cover the build; your written price follows a survey and agreed drawings.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Side return extensions | 11 m² | £24,500 – £31,000 |
| Kitchen extensions | 20 m² | £39,000 – £49,500 |
| Single-storey rear extensions | 20 m² | £38,000 – £48,500 |
| Orangery extensions | 16 m² | £41,500 – £52,500 |
| Double-storey extensions | 32 m² | £53,500 – £70,000 |
Where we work near Caerphilly
Site visits are available across Caerphilly (CF83). The same team covers Risca (6 miles), Pontypridd (6 miles), Gelligaer (6 miles), Blackwood (6 miles), Tonypandy (11 miles), all within easy reach. Just over the South Glamorgan border, Cardiff is about 7 miles away.
Choosing the right extension in Caerphilly
In Wales, terraced houses with rear offshoots are common in the towns, while detached houses and bungalows dominate in rural areas.
The types we would usually look at first for a home in Caerphilly are bungalow extensions, pitched roof extensions and single-storey rear extensions, depending on the garden and how the house is laid out.
Planning and building control in Caerphilly
In Wales a single-storey rear extension can usually project up to 4 m beyond the rear wall without a planning application, if it is no more than 4 m high, keeps eaves to 3 m and overall height to 4 m within 2 m of a boundary, and covers no more than half the land around the original house. Wales has no larger home extension prior approval scheme.
In Wales a single-storey side return can fall within permitted development if it stays within the 4 m height limit and the width rules for side extensions. Conservation areas and listed buildings need consent, and the Party Wall Act applies to work on or near a shared wall.
In a conservation area, national park, National Landscape or World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
The Party Wall etc. Act 1996 applies in Wales as in England: notice must be served before work to a shared wall, building on the boundary, or excavating close to a neighbour's foundations.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
All extension types we build in Caerphilly
- Glass box extensions · from £27,500
- Pitched roof extensions · from £20,500
- Kitchen extensions · from £25,000
- Timber frame extensions · from £19,500
- Bedroom extensions · from £24,000
- Building regulations for extensions · from £800
- Extensions over a garage · from £22,000
- Side extensions · from £20,000
- Wraparound extensions · from £33,000
- Home office extensions · from £14,500
- Conservatory replacement extensions · from £18,500
- Flat roof extensions · from £19,500
- Planning permission for extensions · from £300
- Single-storey rear extensions · from £19,500
- Side return extensions · from £16,500
- Porch extensions · from £3,700
- Orangery extensions · from £27,500
- Utility and boot room extensions · from £13,000
- Double-storey extensions · from £35,000
- Annexe extensions · from £51,000
- Bungalow extensions · from £24,000
- Extension plans and drawings · from £1,100
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions about extensions in Caerphilly
How much does an extension cost in Caerphilly?
Using our Wales factor (×0.93), a standard-spec single-storey extension of 20 m² is a guide £38,000 to £48,500 including VAT, and a 32 m² two-storey extension £53,500 to £70,000. Your written price follows the survey.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Caerphilly, and the guide-price tool gives a range for your own size and finish in about a minute.
Will my neighbours need to be told?
If you apply for planning the council notifies them, and in Wales party wall notices may be needed for work near a shared boundary.
Do I need planning permission for an extension in Caerphilly?
Not always. It depends on the size, position and your property's history. In Wales many single-storey rear extensions up to 4 m are permitted development.
Book a free site visit in Caerphilly
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.