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 Preston 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 PR1 and PR2, and a typical project of this kind in the North West lands somewhere in the £33,000–£71,000 bracket, including VAT. The exact figure depends on size, access and the finish you choose.
- Guide price
- £33,000–£71,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- PR1 and PR2
- Planning rules
- England
- Local area
- Lancashire
- Survey
- Free, with a written quote
How much does a single-storey extension cost in Preston?
Every figure below is a guide for a single-storey extension in Preston, 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 Preston |
|---|---|---|
| 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 |
Your price depends mostly on:
- 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
- Building control inspections and completion certificate
Homes in Lancashire
East Lancashire mill towns such as Burnley, Blackburn and Accrington have long rows of stone and brick terraces, while Preston is mostly red brick. Lancaster uses sandstone for its Georgian centre, Blackpool and the Fylde coast have guest-house terraces and many bungalows, and interwar and newer estates surround most towns.
Mill-town terraces commonly suit attic conversions, kitchen extensions and repointing. Bungalows on the coast often take loft rooms and porches, and stone properties may need lime pointing and roof repairs.
In Preston, as elsewhere in Lancashire, we take the building's age and construction into account before recommending anything, because both can change what is involved in a single-storey extension.
Permissions for a single-storey extension in Preston
Planning law differs across the UK. For a home in Preston, it is the England rules below that count, and we check them with the council ahead of any 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.
What happens after you get in touch?
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.
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.
Dates and permissions
We handle the paperwork side: checking whether planning permission or building control approval is needed, submitting applications where they are, and scheduling the trades and materials around your dates.
On site to finish
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.
What you can expect from us
Frequently asked questions
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.
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.
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 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.
Which postcodes in Preston do you cover?
We cover PR1 and PR2, along with the rest of Lancashire. 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.
Also covering areas around Preston
Whether you're in the centre of Preston or on its outskirts, PR1 and PR2 addresses are covered. We extend the same service, and the same fixed-price approach, to Leyland, Chorley and Blackburn.