Monmouth, Newport and Monmouthshire
Side return extension in Monmouth
Infilling the narrow passage beside a Victorian or Edwardian back addition. If you live in Monmouth and want to know what a side return extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Monmouth and its postcode districts NP25 are part of our Newport and Monmouthshire coverage. In Monmouth we check the boundary line and the neighbour's gutter before drawing a side return, because a few centimetres decide whether the wall goes on or beside the boundary.
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 side return extension cost in Monmouth?
Guide prices for a side return extension in Monmouth start from our Wales rate of £2,140–£3,530 per square metre, including VAT. Prices in Wales sit below our West Midlands baseline; sloping sites are the main variable.
| Size | Guide price inc VAT |
|---|---|
| 2 m wide × 6 m deep (12 m²) | £25,500–£42,500 |
| 2.5 m wide × 7 m deep (17.5 m²) | £37,500–£62,000 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a side return extension in Monmouth?
Whether your side return extension in Monmouth needs a planning application depends on its size, your house and any local restrictions.
In Wales a single-storey side extension can be permitted development if it is no more than 4 metres high and the house ends up no more than 50% wider than the original. Many side return infills on terraced streets, and most wraparounds, go through a householder application.
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. 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 Monmouth like to extend?
Older terraces near the centre and post-war semis further out are typical of Monmouth. Sloping sites are common in Wales, so floor levels and retaining walls are designed at the start.
How a side return extension in Monmouth 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.
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.
Side return extensions near Monmouth
Neighbouring places we cover include Cinderford (9.2 miles) and Ross on Wye (9.5 miles).
- Side return extension in Cinderford
- Side return extension in Ross on Wye
- Side return extension in Chepstow
- Side return extension in Abergavenny
- Side return extension in Caldicot
Other work in Monmouth:
FAQ
Side return extension questions in Monmouth
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 planning permission for a rear extension in Monmouth?
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.
Is a side return permitted development?
Sometimes, as a side extension within the width and height limits, but not in conservation areas, and many terraces are in one.
Can you match the brick or stone on my Monmouth house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
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.
Is the site visit in Monmouth free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.