Milford Haven, West Wales
Semi-detached rear extension in Milford Haven
Single or two-storey extensions for semi-detached houses, with side access and one party wall. If you live in Milford Haven and want to know what a semi-detached rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Milford Haven is covered from our West Wales round, including SA73. Where a Milford Haven 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 Milford Haven?
For Milford Haven we work from the Wales rate: £1,770–£2,880 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 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 |
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 for a semi-detached rear extension in Milford Haven?
Here is how the rules in Wales apply to a semi-detached rear extension in Milford Haven.
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. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Milford Haven like to extend?
Milford Haven 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 a semi-detached rear extension in Milford Haven comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Approvals
Permitted development check or householder planning application, then Building Regulations drawings to the Welsh Approved Documents and structural calculations, plus party wall notices where they apply.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Semi-detached rear extensions near Milford Haven
We also build rear extensions for semi-detached houses in nearby Haverfordwest (6.7 miles) and Carmarthen (32.7 miles).
- Semi-detached rear extension in Haverfordwest
- Semi-detached rear extension in Carmarthen
- Semi-detached rear extension in Llanelli
- Semi-detached rear extension in Gorseinon
- Semi-detached rear extension in Ammanford
Other work in Milford Haven:
FAQ
Semi-detached rear extension questions in Milford Haven
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.
What postcode areas do you cover around Milford Haven?
Including SA73, and the surrounding West Wales area.
How long does a semi extension take?
10 to 16 weeks on site for a single-storey extension.
Is the site visit in Milford Haven free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
How long does a rear extension take to build in Milford Haven?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.