A double-storey extension adds two floors of new space to your house in one build, typically a larger kitchen or living room downstairs with an extra bedroom, bathroom or en-suite above, sharing one set of foundations and one roof.
Planning a double-storey extension for a home in Preston means making a handful of decisions about materials, layout, finish and timing. We help you work through them at a free survey, then confirm in writing what it will cost for the options you pick. Most projects of this type need 14–22 weeks on site, and we cover every PR1 and PR2 address as well as the rest of Lancashire.
- Guide price
- £57,000–£114,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- PR1 and PR2
- Planning rules
- England
- Local area
- Lancashire
- Survey
- Free, with a written quote
What should you budget for a double-storey extension in Preston?
The costs listed here are typical for a double-storey extension around Preston and include VAT. They reflect labour and material costs in the North West, about 5% below the national guide, giving a range of £57,000–£114,000. Exact pricing depends on your home, so we only fix it once a free site survey is done.
| Type of job | What it usually involves | Guide in Preston |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £38,000–£62,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £57,000–£114,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £95,000–£171,000 |
What moves the price up or down:
- Combined floor area across both storeys
- How the new roof joins the existing roof
- Bathrooms, en-suites and plumbing on the upper floor
- Scaffolding duration, access and the level of finishes
What do you get?
- Groundworks, foundations and below-ground drainage
- Insulated cavity walls with brick or render to match the house
- First-floor joists, stud walls and new openings upstairs
- Roof structure tied into the existing roof, tiled to match
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Building in Preston
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.
For a double-storey extension in Preston, this means checking things like wall construction, roof structure and existing services before we put a figure on paper.
Planning and building rules in Preston
Each UK nation sets its own consent rules, and Preston is in England. What follows is a plain summary; we check the specifics for your property with the council before pricing anything.
In England, a two-storey rear extension can only be permitted development if it is no more than 3 m deep, at least 7 m from the rear boundary and finished to match the house. Most double-storey and all two-storey side extensions need full planning permission.
Building Regulations approval is needed, with structural calculations for beams, foundations and the roof. The Party Wall etc. Act 1996 often applies on semi-detached and terraced houses.
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
First, someone visits your home in Preston to see the space, take measurements and note anything that could affect the work, such as access or the condition of what is there. There is no charge for this visit.
Written quote
You get the price in writing, itemised so you can see where the money goes. As long as the specification stays the same, that is the price you pay for a double-storey extension.
Booking the work
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
On site to finish
The job proceeds in the order set out in the programme, with dust and debris kept under control. Finally we tidy away, inspect the work together and pass the finished project over to you with its paperwork.
What you can expect from us
Common questions
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.
Will the extension affect my neighbours?
A double-storey extension can affect neighbours' light, outlook and privacy, which is why planning departments look closely at height, depth and window positions. Side windows facing neighbours often need obscure glass. Work near a shared wall may also need party wall notices; the Party Wall etc. Act 1996 applies in England and Wales only. We talk through these points early so the design is realistic.
Do I need planning permission for a two-storey extension?
Most two-storey extensions need planning permission, but it depends on the size, height and position, your home's location, whether it is listed or in a conservation area, and which UK nation you are in. In England, a two-storey rear extension can sometimes be built under permitted development if it is no deeper than 3m and at least 7m from the rear boundary. We check what applies before quoting.
How long does a double-storey extension take?
A double-storey extension typically takes 14–22 weeks on site, depending on size, roof design and weather. Foundations and ground-floor walls come first, then the first-floor joists, upper walls and roof. Once it is weathertight, electrics, plumbing, plastering and finishes follow. Allow extra time beforehand for drawings, calculations and approvals. We give you a stage-by-stage programme with your quote.
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.
Near Preston
Addresses in PR1 and PR2 are all covered for Preston, along with Leyland, Chorley and Blackburn close by. Give us your postcode when you get in touch and we will confirm the details.

