Newport and Monmouthshire
Two-storey rear extensions in Newport and Monmouthshire
A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. Rear extensions in Newport and Monmouthshire: we cover 6 towns including Newport, Abergavenny and Chepstow, with design, approvals and the build under one contract.

Two-storey rear extensions suit semi-detached houses in Newport best, where the extra bedroom matters as much as the bigger kitchen. Newport and Monmouthshire has Victorian terraces near the centre and semis further out. Welsh permitted development allows up to 4 metres at the rear for many houses.
How much does a two-storey rear extension cost in Newport and Monmouthshire?
For Newport and Monmouthshire we work from the Wales rate: £1,670–£2,510 per square metre of new floor, including VAT, standard specification. 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 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission in Newport and Monmouthshire?
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.
Where in Newport and Monmouthshire do we work?
FAQ
Questions people ask
Does a two-storey rear extension need planning permission?
Almost always. England and Northern Ireland allow 3 metres without an application only if at least 7 metres remains to the rear boundary; Wales and Scotland are similar or stricter.
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 add an en-suite upstairs?
Yes. We plan the soil pipe route early so the bathroom sits where drainage works without boxing through the room below.
Do you cover all of Newport and Monmouthshire?
We cover 6 towns and districts in Newport and Monmouthshire, including Newport, Abergavenny and Chepstow.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.