Nelson, South Wales Valleys
Semi-detached rear extension in Nelson
For homes in Nelson, a semi-detached rear extension is often the simplest way to gain space without moving. Single or two-storey extensions for semi-detached houses, with side access and one party wall. We take it from survey to completion certificate.
Nelson sits in the South Wales Valleys, with postcode districts including CF46. Where a Nelson semi already has a small lean-to at the back, we usually replace it rather than extend it.
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 semi-detached rear extension cost in Nelson?
In Nelson, our guide for a semi-detached rear extension is £1,770–£2,880 per square metre including VAT for a standard specification. Prices in Wales sit below our West Midlands baseline; sloping sites are the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £21,000–£34,500 |
| 4 m wide × 5 m deep (20 m²) | £35,500–£57,500 |
| 4 m wide × 6 m deep (24 m²) | £42,500–£69,000 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a semi-detached rear extension in Nelson?
Planning for a semi-detached rear extension in Nelson follows the Welsh householder rules.
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 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. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Nelson like to extend?
Stone terraces along the valley floors and post-war semis higher up are typical of Nelson. Sloping sites are common, so floor levels and retaining walls are designed at the start.
How a semi-detached rear extension in Nelson comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
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.
Semi-detached rear extensions near Nelson
We also build rear extensions for semi-detached houses in nearby Treharris (1.2 miles) and Gelligaer (1.4 miles).
- Semi-detached rear extension in Treharris
- Semi-detached rear extension in Gelligaer
- Semi-detached rear extension in Bargoed
- Semi-detached rear extension in Blackwood
- Semi-detached rear extension in Pontypridd
Other work in Nelson:
FAQ
Semi-detached rear extension questions in Nelson
Do I need planning permission for a rear extension in Nelson?
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.
What postcode areas do you cover around Nelson?
Including CF46, and the surrounding South Wales Valleys area.
How long does a semi extension take?
10 to 16 weeks on site for a single-storey extension.
Do you handle building control in Nelson?
Yes. We apply to the council or a registered approver under the Welsh regulations and hand over the completion certificate.
Can you match the brick or stone on my Nelson house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Is the site visit in Nelson free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.