Caerphilly, South Wales Valleys
Two-storey rear extension in Caerphilly
A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. If you live in Caerphilly and want to know what a two-storey rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Caerphilly and its postcode districts CF83 are part of our South Wales Valleys coverage. In Caerphilly, a two-storey rear extension is worth comparing with the cost of moving once stamp duty, agents' and legal fees are counted.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a two-storey rear extension cost in Caerphilly?
A two-storey rear extension in Caerphilly is priced at £1,670–£2,510 per square metre including VAT as a guide, before kitchen fit-out and fees. Prices in Wales sit below our West Midlands baseline; sloping sites are the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £50,000–£75,500 |
| 4 m × 6 m footprint, two floors (48 m²) | £80,500–£120,500 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a two-storey rear extension in Caerphilly?
The planning route for a two-storey rear extension in Caerphilly is set by Wales's householder rules and your council.
In Wales a rear extension of more than one storey can be permitted development if the ground floor projects no more than 4 metres and the upper floor no more than 3 metres, with at least 10.5 metres to the rear boundary. It is not permitted development in conservation areas, National Parks or National Landscapes, so many double-storey schemes need a householder application.
Conservation areas, National Parks and National Landscapes restrict permitted development in Wales, and listed buildings need listed building consent. At the first visit we measure what is there now and tell you which route fits: permitted development or a householder planning application.
What are homes in Caerphilly like to extend?
Stone terraces along the valley floors and post-war semis higher up are typical of Caerphilly. Sloping sites are common, so floor levels and retaining walls are designed at the start.
How a two-storey rear extension in Caerphilly comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Two-storey rear extensions near Caerphilly
Close by, we work in Rhiwbina, about 3.2 miles away, and Whitchurch, about 4.3 miles away.
- Two-storey rear extension in Rhiwbina
- Two-storey rear extension in Whitchurch
- Two-storey rear extension in Risca
- Two-storey rear extension in Pontypridd
- Two-storey rear extension in Nelson
Other work in Caerphilly:
FAQ
Two-storey rear extension questions in Caerphilly
Do I need planning permission for a rear extension in Caerphilly?
Often not for a single-storey rear extension of up to 4 metres under Welsh permitted development. Wales has no prior approval route for deeper extensions.
Can you match the brick or stone on my Caerphilly house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Is two-storey cheaper per square metre than single-storey?
Usually yes, because the foundations and roof are shared across twice the floor area. The total cost is higher.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Do I need a party wall agreement?
In Wales, usually yes if the extension is on or near a shared boundary or close to a neighbour's foundations. We serve the notices.