A single-storey extension is a new ground-floor room built onto your house, usually at the rear or side, with its own foundations, walls and roof, creating a bigger kitchen, living space or bedroom without moving home.
If you live in Mirfield and are weighing up a single-storey extension, the starting point is a visit to measure up and talk through what you want, which costs nothing. We cover homes across WF14, and a typical project of this kind in Yorkshire and the Humber lands somewhere in the £33,000–£70,000 bracket, including VAT. The exact figure depends on size, access and the finish you choose.
- Guide price
- £33,000–£70,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- WF14
- Planning rules
- England
- Local area
- Kirklees
- Survey
- Free, with a written quote
Single-storey extensions prices in Mirfield
What will a single-storey extension cost in Mirfield? Our guide range is £33,000–£70,000 including VAT. That figure is adjusted for Yorkshire and the Humber, about 6% below the national guide, and is intended for planning a budget. A firm written price for your chosen specification follows a free survey at your home.
| Type of job | What it usually involves | Guide in Mirfield |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £20,500–£37,500 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £33,000–£70,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £66,000–£122,000 |
The main things that change the figure:
- Roof type, rooflights, lanterns and the amount of glazing
- Ground conditions, foundation depth and drains to divert
- Steelwork needed to open into the existing house
- Finishes, kitchen, flooring and heating specification
Scope of the work
- Groundworks, foundations and below-ground drainage
- Flat or pitched roof, with rooflights or a lantern if specified
- Electrics and plumbing by qualified trades, with certificates
- Windows and external doors, including bifolds if chosen
- Plastering, screed floor and internal doors
- Building control inspections and completion certificate
Building in Mirfield
Leeds and Bradford are known for back-to-back and through terraces, many in sandstone or millstone grit, with stone-slate roofs on older properties. Halifax, Huddersfield and the Calder valley have mill-town stone terraces climbing steep hillsides, and interwar semis, post-war estates and newer housing surround the larger towns.
The Pennine hills bring high rainfall, wind and frost, and the Calder valley has a history of serious flooding.
For a single-storey extension in Mirfield, this means checking things like wall construction, roof structure and existing services before we put a figure on paper.
Permissions for a single-storey extension in Mirfield
As Mirfield is in England, read the following with that system of planning and building control in mind. We check what applies to your house with the council before you receive a quote.
In England, many single-storey rear extensions are permitted development: typically up to 3 m deep on a semi-detached or terraced house and 4 m on a detached house, no more than 4 m high, and covering no more than half the land around the original house. Larger rear extensions can go through the prior approval process. Side extensions, flats, listed buildings, conservation areas and homes where permitted development rights have been removed need planning permission.
Building Regulations approval is needed for almost every extension, covering foundations, structure, insulation, drainage, ventilation and fire safety. If the work is on or near a shared wall or boundary, the Party Wall etc. Act 1996 may apply.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
From survey to handover
A visit to your home
We arrange a free site survey on a date convenient to you. We measure up, look at the existing structure and access, and discuss your plans for a single-storey extension so the price reflects your home.
Quote in writing
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
Getting ready
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Mirfield property.
The work itself
On site, the agreed plan is followed and any change is put in writing first. At completion we do a final clean, go through the snagging list with you and leave you with the relevant documents.
Why homeowners choose us
Single-storey extensions in Mirfield: questions
What does a typical extension build look like week by week?
A typical single-storey extension follows the same order: clearing the site and digging foundations, building walls up to roof level, then fitting the roof and windows to make it weathertight. Electrics, plumbing, insulation and plastering follow. The last stage is opening into the house, laying the screed and fitting doors and finishes. Building control inspects at key stages, and we book those visits for you.
Is the price fixed?
Yes, for the specification we agree. Your written quote sets out exactly what is included at a fixed price. It only changes if you ask for something different, or if a problem the survey could not reasonably reveal later needs extra work. In either case we explain the change and confirm it in writing before going ahead.
Can we stay at home during the build?
Most people stay at home while we build a single-storey extension, because the new structure goes up outside before we break through. The disruptive part is usually the last few weeks, when we open into the house and fit the kitchen. We put up dust screens, keep a safe route through the house and agree a temporary kitchen setup if needed. Water and power are only off for short, planned periods.
Which postcodes in Mirfield do you cover?
We cover WF14, along with the rest of West Yorkshire. If your postcode is not listed, get in touch anyway: our coverage is UK-wide, and we can usually arrange a survey wherever you live. Enter your postcode in the guide-price tool or contact form and we will confirm.
Is a flat roof or a pitched roof better on an extension?
A flat roof is quicker to build and usually costs less, gives a clean modern look and works well with a roof lantern. A pitched roof matches the main house, sheds water faster and allows a vaulted ceiling, but it costs more and its height can affect neighbours. Modern flat roofs in EPDM rubber or GRP last well when properly detailed. Planning rules on height can also decide the choice.
Nearby towns
We survey and quote throughout Mirfield's WF14 postcodes and in surrounding places such as Liversedge, Heckmondwike and Dewsbury. The process and pricing approach are identical in each of them.