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.
We offer a single-storey extension across Cheshire, and Widnes is one of the places we cover, along with nearby Runcorn, Halewood and Great Sankey. Before anything is agreed we visit, check the existing structure and talk through your options. You then receive a written quote setting out the full scope; for most homes in the North West it sits within £33,000–£71,000 including VAT.
- Guide price
- £33,000–£71,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- WA8
- Planning rules
- England
- Local area
- Halton
- Survey
- Free, with a written quote
How much does a single-storey extension cost in Widnes?
No two jobs cost exactly the same, but the ranges below give a fair picture of a single-storey extension in Widnes. Pricing for the North West runs about 5% below the national guide, and the overall guide is £33,000–£71,000 with VAT included. We'll confirm your figure after surveying the property for free.
| Type of job | What it usually involves | Guide in Widnes |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £21,000–£38,000 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £33,000–£71,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £66,000–£124,000 |
What moves the price up or down:
- Floor area, shape and number of corners
- 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
What’s included?
- Groundworks, foundations and below-ground drainage
- Steel beams to open into the existing house
- 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
Homes in Cheshire
Chester mixes Georgian and Victorian terraces with black-and-white revival frontages, and red sandstone shows up across the west of the county. Crewe has railway-era brick terraces, Macclesfield has mill workers' cottages, and Wilmslow, Knutsford and Alderley Edge are known for large detached homes. Interwar semis and newer estates surround Warrington and Northwich.
The Cheshire Plain is fairly mild, but rainfall rises towards the Pennine edge, and parts of mid Cheshire have a history of subsidence linked to salt extraction.
For a single-storey extension in Widnes, this means checking things like wall construction, roof structure and existing services before we put a figure on paper.
Do you need permission in Widnes?
Each UK nation sets its own consent rules, and Widnes is in England. What follows is a plain summary; we check the specifics for your property with the council before pricing anything.
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
Free site survey
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.
Price and scope agreed
We turn the survey notes into a written quote. The price is fixed for the specification we agree, and the document sets out materials, scope and payment stages in plain language.
Dates and permissions
Preparation matters as much as the build. We agree access, parking and working hours with you, order materials in good time, and confirm any permissions so the job isn't held up once it starts.
On site to finish
Work goes ahead as scheduled and you deal with one contact throughout. When the last trade leaves, we clear and clean the site, talk you through what has been done and pass on any certificates and care instructions.
How we work
Frequently asked questions
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.
Who do I deal with during the job?
One point of contact manages your project from survey to handover. They schedule the trades working under our contract, keep you updated on progress, and are the person to call with any question. You don't need to coordinate builders, electricians or decorators separately, because that is part of what we do.
How much does a single-storey extension cost?
A typical single-storey rear extension of 15–25m² costs £33,000–£71,000, built to a plastered finish ready for your kitchen and decoration. As a guide, allow roughly £1,600–£2,800 per square metre plus fixed costs for groundworks, steelwork and fees. Smaller extensions cost more per square metre. The kitchen, flooring and large glazed doors are usually the biggest extras. We confirm a fixed price for the agreed specification after the survey.
Do I need an architect for an extension?
You need proper drawings for an extension, but not always a full architect service. A designer or architectural technician can produce planning and building regulations drawings, and a structural engineer provides beam and foundation calculations. If you already have drawings, we price from them. If not, we can arrange the drawings and calculations as part of the project so everything is coordinated from the start.
How long will a single-storey extension take?
On a typical home, allow 10–16 weeks on site. Larger projects, older buildings and extra work found once things are opened up can extend that, while simpler jobs may be shorter. Your quote includes an estimate of time on site, and your point of contact keeps you updated on the programme as the work progresses.
Near Widnes
We welcome enquiries from all WA8 postcodes in Widnes, plus Runcorn, Halewood and Great Sankey. Each one gets the same survey at no charge and a written price fixed for the work described.