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.
In Warrington, as anywhere in Cheshire, the price of a single-storey extension is driven mainly by size, materials and access. Across the North West our guide sits at £33,000–£71,000 with VAT, but restricted parking, a narrow side passage or extra preparation can move the figure either way. That is why every price we give follows a visit to the house.
- Guide price
- £33,000–£71,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- WA1, WA2, WA4 and WA5
- Planning rules
- England
- Local area
- Cheshire
- Survey
- Free, with a written quote
What should you budget for a single-storey extension in Warrington?
Every figure below is a guide for a single-storey extension in Warrington, inclusive of VAT. Regional pricing for the North West works out about 5% below the national guide, and the overall span is £33,000–£71,000. The survey costs you nothing, and after it we commit to a firm price for your specification in writing.
| Type of job | What it usually involves | Guide in Warrington |
|---|---|---|
| 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 |
The main things that change the figure:
- Floor area, shape and number of corners
- 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
- Cavity walls built and insulated to building regulations
- 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
What are homes like around Warrington?
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.
None of this holds for every street in Warrington, which is why we look at your actual house before pricing a single-storey extension rather than assuming from its age alone.
Do you need permission in Warrington?
Which rules apply depends on where you live. For Warrington, the answer is England, and the points below reflect that; we verify them with the council before quoting.
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.
What happens after you get in touch?
We look at the job
A free survey comes first. It gives us what we need to price a single-storey extension properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Written quote
After the survey we send a quote for a single-storey extension that fixes the price for the scope we've agreed. If you want to change materials or scope, we revise it in writing before anything is booked.
Plan and prepare
Before anyone starts, we confirm the programme in writing, check whether consents are required and arrange deliveries. If a skip or scaffolding on the road needs a permit, we apply for it.
Build and hand over
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.
Why homeowners choose us
Frequently asked questions
How long does a single-storey extension take to build?
A single-storey extension usually takes 10–16 weeks on site, from digging foundations to final plastering. Bad weather, deep foundations or a complex roof can add time. Before work starts, allow several weeks for drawings, structural calculations and building control approval, and longer if planning permission is needed. We give you a stage-by-stage programme with your quote so you know what happens each week.
What is the Party Wall Act and does it apply to me?
The Party Wall etc. Act 1996 applies in England and Wales only. In England and Wales, it requires you to give notice to neighbours before certain work on or near a shared wall, such as digging foundations within 3m of their building and deeper than its footings. Neighbours can agree or appoint a surveyor. Scotland and Northern Ireland have no equivalent Act, though general rights still apply. We identify whether notices are needed during the survey.
Do you cover Great Sankey, Newton-le-Willows and Golborne?
Yes. As well as Warrington, we cover Great Sankey, Newton-le-Willows and Golborne and the rest of Cheshire. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
How much will a single-storey extension cost in Warrington?
As a guide, expect to pay £33,000–£71,000 including VAT for a single-storey extension in Warrington. That range is adjusted for the North West, which runs about 5% below the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
Do I need planning permission for a single-storey extension?
Whether you need planning permission depends on the extension's size and height, how close it is to boundaries, your home's location, whether it is listed or in a conservation area, and which UK nation you live in. In England, many rear extensions up to 3m deep on a semi or terrace, or 4m on a detached house, can be built under permitted development. We check the rules that apply to your home before quoting.
Near Warrington
We survey and quote throughout Warrington's WA1, WA2, WA4 and WA5 postcodes and in surrounding places such as Great Sankey, Newton-le-Willows and Golborne. The process and pricing approach are identical in each of them.

