Kilmarnock, Ayrshire
Semi-detached rear extension in Kilmarnock
For homes in Kilmarnock, 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.
Kilmarnock sits in Ayrshire, with postcode districts including KA1. Semi-detached houses are common across Ayrshire, and their side access makes rear extensions quicker to build.
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 Kilmarnock?
For Kilmarnock we work from the Scotland rate: £1,800–£2,940 per square metre of new floor, including VAT, standard specification. 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 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a semi-detached rear extension in Kilmarnock?
Whether your semi-detached rear extension in Kilmarnock needs a planning application depends on its size, your house and any local restrictions.
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. 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 Kilmarnock like to extend?
Post-war semis and terraces are common around Kilmarnock, and many have room for a single-storey rear extension within Class 1A limits.
How a semi-detached rear extension in Kilmarnock comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Approvals
Permitted development check or planning application, then building warrant drawings and structural calculations, plus a written agreement with neighbours for any shared-wall work.
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 Kilmarnock
From Kilmarnock, the nearest places we also cover are Irvine (6.2 miles) and Troon (8.1 miles).
- Semi-detached rear extension in Irvine
- Semi-detached rear extension in Troon
- Semi-detached rear extension in Kilwinning
- Semi-detached rear extension in Prestwick
- Semi-detached rear extension in Saltcoats
Other work in Kilmarnock:
FAQ
Semi-detached rear extension questions in Kilmarnock
Do I need a party wall agreement?
Scotland has no Party Wall Act; we agree access and protection with your neighbour in writing instead.
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.
What if my neighbour has already extended?
That can make a matching depth easier to justify. We measure theirs at the survey.
Can you match the brick or stone on my Kilmarnock house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
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.
Is the site visit in Kilmarnock free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.