Wales
Rear extensions in Newport and Monmouthshire
Across Newport and Monmouthshire we handle the whole rear extension: survey, drawings, the planning route, building control and the build. Towns we cover here include Newport, Abergavenny and Chepstow.

What are homes in Newport and Monmouthshire like to extend?
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.
Rear extension prices in Newport and Monmouthshire
Prices in Wales sit below our West Midlands baseline; sloping sites are the main variable. Per square metre including VAT, standard specification:
| Extension | Per m² |
|---|---|
| Single-storey rear extension | £1,770–£2,880 |
| Two-storey (per m² across both floors) | £1,670–£2,510 |
| Side return | £2,140–£3,530 |
| Wraparound | £2,050–£3,350 |
| Glass-led | £2,600–£4,460 |
Planning and building rules in Newport and Monmouthshire
The Welsh Government's householder rules let many homes add a single-storey rear extension up to 4 metres deep and 4 metres high without a planning application. Deeper projects go through a householder application, because Wales has no prior approval route.
In Wales a rear extension needs Building Regulations approval through the council or a registered approver, and is built to the Welsh Approved Documents, which differ from England's in places, including energy efficiency.
The Party Wall etc. Act 1996 also applies in Wales: two months' notice for work to a shared wall and one month for foundations dug close to a neighbour's building.
Conservation areas, National Parks and National Landscapes restrict permitted development in Wales, and listed buildings need listed building consent.
Rear extensions we build in Newport and Monmouthshire
- Permitted development rear extensions
- Rear extension plans and planning applications
- Building Regulations for rear extensions
- Single-storey rear extensions
- Two-storey rear extensions
- Kitchen-diner rear extensions
- Side return extensions
- Wraparound extensions
- Glazed and glass-box rear extensions
- Rear extensions for terraced houses
- Rear extensions for semi-detached houses
- Rear extensions for detached houses
- Rear extensions for bungalows
- Flat-roof rear extensions
- Pitched and lean-to roof rear extensions
- Knocking through to a rear extension
- Roof lanterns and rooflights for rear extensions
Towns and districts in Newport and Monmouthshire
The main places we cover in Newport and Monmouthshire include Newport, Abergavenny and Chepstow, across postcode areas NP.
| Town | Postcode districts | Nearest town we also cover |
|---|---|---|
| Newport | NP10, NP18, NP19 | Caerleon (2.4 miles) |
| Abergavenny | NP7 | Brynmawr (7.2 miles) |
| Chepstow | NP16 | Caldicot (5.1 miles) |
| Monmouth | NP25 | Cinderford (9.2 miles) |
| Caldicot | NP26 | Chepstow (5.1 miles) |
| Caerleon | NP18 | Newport (2.4 miles) |
Areas near Newport and Monmouthshire
FAQ
Questions people ask
How much does a rear extension cost in Newport and Monmouthshire?
As a guide, £1,770–£2,880 per square metre including VAT for a standard single-storey extension at Wales rates.
Do I need planning permission in Newport and Monmouthshire?
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.
Which towns in Newport and Monmouthshire do you cover?
6 towns and districts, including Newport, Abergavenny and Chepstow.
Do you handle building control?
Yes. We apply to the council or a registered approver under the Welsh regulations and hand over the completion certificate.