Annexe extensions across Mirfield
A annexe extension in Mirfield starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in MirfieldFrom £51,500 inc VAT
- PlanningUsually a householder application
- Build time16–24 weeks on site
- Postcode districtsWF14
What is included
- Design for accessibility: level thresholds, wider doors, walk-in shower
- Separate or shared heating and hot water
- Planning application describing ancillary use
- Fire separation and alarms to building regulations
- Kitchenette, shower room and bedroom finish
Will the council need to approve it?
In England an annexe that stays part of the household and connects to the house is assessed as an extension, but its size usually takes it beyond permitted development, so a householder application describing the ancillary use is the normal route.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
Local to Mirfield
Site visits are available across Mirfield (WF14). The same team covers Liversedge (2 miles), Heckmondwike (2 miles), Dewsbury (3 miles), Batley (3 miles), all within easy reach.
Yorkshire and the Humber combines stone-built terraces in the Pennine towns with brick semis and newer estates elsewhere, so materials and roof details need matching with care.
How much does an annexe extension cost in Mirfield?
Labour and material costs vary across the UK, so for Mirfield we use our Yorkshire and the Humber factor (×0.94). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Mirfield: £1,880 to £3,570 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Studio annexe 25 m² | £51,500 – £65,000 | £56,000 – £70,500 | £70,500 – £89,500 |
| One-bedroom annexe 35 m² | £65,500 – £82,500 | £78,500 – £99,000 | £98,500 – £125,500 |
| Larger annexe 45 m² | £84,500 – £106,000 | £101,500 – £127,000 | £126,500 – £161,000 |
For a figure based on your own dimensions, use our guide-price tool.
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Your questions about an annexe extension in Mirfield
Do I need building regulations approval in Mirfield?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Mirfield, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Will my neighbours in Mirfield be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Can the annexe have its own front door?
Yes, many do, but it should still connect to the main house to stay clearly part of it.
How much does an annexe extension cost?
Our guide range is about £1,880 to £3,570 per m² including VAT. A one-bedroom annexe of about 35 m² is typically £78,500 to £99,000 at standard spec in Mirfield.
Book a free site visit in Mirfield
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.