Ardrossan, Ayrshire
Semi-detached rear extension in Ardrossan
Single or two-storey extensions for semi-detached houses, with side access and one party wall. We design, get the approvals for and build rear extensions for semi-detached houses in Ardrossan and the surrounding area, with one contract from the first survey to building control sign-off.
Ardrossan and its postcode districts KA21 and KA22 are part of our Ayrshire coverage. Where an Ardrossan 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 Ardrossan?
Guide prices for a semi-detached rear extension in Ardrossan start from our Scotland rate of £1,800–£2,940 per square metre, including VAT. Prices in Scotland sit a little below our West Midlands baseline; building warrant fees and drawings are budgeted separately.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £21,500–£35,500 |
| 4 m wide × 5 m deep (20 m²) | £36,000–£59,000 |
| 4 m wide × 6 m deep (24 m²) | £43,500–£70,500 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a semi-detached rear extension in Ardrossan?
Planning for a semi-detached rear extension in Ardrossan follows the Scottish householder rules.
In Scotland a single-storey rear extension can be permitted development under Class 1A: eaves no higher than 3 metres and an overall height of 4 metres, and where any part is within 1 metre of a boundary it can project no more than 3 metres on a terraced house or 4 metres on other houses. The rights do not apply in conservation areas, and a building warrant is still needed before work starts.
In Scotland an extension of more than one storey is only permitted development (Class 1B) if no part is within 10 metres of any boundary and it is no higher than the existing house, so almost every two-storey rear extension needs planning permission and a building warrant.
Scotland has no larger-extension prior approval route; extensions beyond permitted development need a planning application.
Classes 1A and 1B do not apply in conservation areas, 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 Ardrossan like to extend?
Post-war semis and terraces are common around Ardrossan, and many have room for a single-storey rear extension within Class 1A limits.
How a semi-detached rear extension in Ardrossan 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.
Paperwork handled
Planning or permitted development, the building warrant, structural design and neighbour agreements are all handled by us.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the accepted completion certificate.
Semi-detached rear extensions near Ardrossan
Close by, we work in Saltcoats, about 1.3 miles away, and Kilwinning, about 3.9 miles away.
- Semi-detached rear extension in Saltcoats
- Semi-detached rear extension in Kilwinning
- Semi-detached rear extension in Irvine
- Semi-detached rear extension in Troon
- Semi-detached rear extension in Largs
Other work in Ardrossan:
FAQ
Semi-detached rear extension questions in Ardrossan
What postcode areas do you cover around Ardrossan?
Including KA21 and KA22, and the surrounding Ayrshire area.
Do I need planning permission for a rear extension in Ardrossan?
Many single-storey rear extensions are permitted development under Class 1A, but not in conservation areas; you always need a building warrant before work starts.
Single or two-storey on a semi?
Two-storey if you need bedrooms, single-storey if you need a bigger kitchen. Planning risk is lower for single-storey.
How long does a rear extension take to build in Ardrossan?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Can you match the brick or stone on my Ardrossan house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Do you handle building control in Ardrossan?
Yes. We apply for the building warrant before work starts and submit the completion certificate at the end.