Mirfield, West Yorkshire
Single-storey rear extension in Mirfield
Ground-floor space across the back of the house, usually for a kitchen, dining or family room. We design, get the approvals for and build single-storey rear extensions in Mirfield and the surrounding area, with one contract from the first survey to building control sign-off.
Mirfield sits in West Yorkshire, with postcode districts including WF14. A single-storey rear extension in Mirfield is mostly built from the garden side, so the house stays usable for most of the job.
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 single-storey rear extension cost in Mirfield?
For Mirfield we work from the Yorkshire and the Humber rate: £1,770–£2,880 per square metre of new floor, including VAT, standard specification. Yorkshire prices sit below our West Midlands baseline; matching natural stone is 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 single-storey rear extension in Mirfield?
Whether your single-storey rear extension in Mirfield needs a planning application depends on its size, your house and any local restrictions.
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always 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 Mirfield like to extend?
Mirfield has through terraces and some back-to-backs as well as later semis; back-to-backs have little or no rear space, so we look at side or loft options there.
How a single-storey rear extension in Mirfield 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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
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.
Single-storey rear extensions near Mirfield
Close by, we work in Liversedge, about 2.2 miles away, and Heckmondwike, about 2.4 miles away.
- Single-storey rear extension in Liversedge
- Single-storey rear extension in Heckmondwike
- Single-storey rear extension in Dewsbury
- Single-storey rear extension in Batley
- Single-storey rear extension in Cleckheaton
Other work in Mirfield:
FAQ
Single-storey rear extension questions in Mirfield
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.
Do you handle building control in Mirfield?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Do I need a structural engineer?
Yes for the beam over the new opening and usually for the foundations. Their calculations go to building control with the drawings.
What postcode areas do you cover around Mirfield?
Including WF14, and the surrounding West Yorkshire area.
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.
How much does a single-storey rear extension cost in Mirfield?
As a guide, £1,770–£2,880 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £21,000–£34,500 at that rate. Your written price follows the survey.