If you are pricing up an extension in Preston, you will find plenty of national cost guides that quote London figures which simply do not apply here. Labour and build costs in Lancashire are noticeably lower than the South East, but your final bill still depends heavily on size, specification and the quirks of your own house. This guide sets out realistic local ranges so you can budget with your eyes open.
For a straightforward single-storey extension in the Preston area, most homeowners should budget somewhere between £1,700 and £2,300 per square metre for the basic build. That means a modest 4m x 5m rear extension (20 square metres) typically lands between £34,000 and £46,000 before you add a kitchen, bathroom or high-end glazing. A two-storey extension usually works out cheaper per square metre, often £1,500 to £2,000, because the foundations and roof are shared across two floors of extra space.
These figures cover the structural shell, standard windows and doors, plastering, basic electrics and heating. They do not include fitting out. A new kitchen can add anywhere from £8,000 for sensible units to £25,000 or more for bespoke, and a bathroom typically adds £5,000 to £10,000. VAT, professional fees and building control charges sit on top, which is why two quotes for the same room can look very different depending on what each one includes.
The biggest cost drivers are rarely the bricks. Ground conditions matter a great deal: parts of Preston, particularly closer to the Ribble and in areas with older clay soils, can need deeper foundations, and if you are near trees or old drains you may need engineered solutions that add several thousand pounds before anything appears above ground. Victorian terraces around Ashton, Fulwood and Plungington often throw up surprises once walls are opened, whereas newer estates in Cottam or Buckshaw tend to be more predictable.
Specification is the other lever you actually control. Bifold or sliding doors, roof lanterns, underfloor heating and steel-framed open-plan layouts all add real money. A structural steel to remove the wall between old and new space, with the engineer's design, typically adds £2,000 to £5,000 depending on the span.
Many single-storey rear extensions fall under permitted development, meaning no planning application is needed if you stay within the size limits, which is generally up to 3m deep on an attached house or 4m on a detached one, extendable further under prior approval. If you do need a planning application to Preston City Council, the fee is a few hundred pounds, plus drawings. Expect architectural drawings and a structural engineer to cost £1,500 to £4,000 combined for a typical project.
Every extension needs building regulations approval regardless of planning, with inspections at key stages. Budget £500 to £1,000 for building control fees. If you share a wall with a neighbour, the Party Wall Act may apply, and while many neighbours simply consent, a formal surveyor process can add £1,000 or more. None of these are optional, so include them in your budget from day one rather than discovering them halfway through.
The most common cause of budget blow-ups is not builders overcharging, it is quotes that cover different things. Ask every builder to price the same drawings and to state clearly what is excluded: kitchen supply, tiling, decoration, skip hire and VAT are the usual gaps. A detailed written quote broken into stages is worth far more than a low round number scribbled after a ten-minute visit.
Locally, decent builders are booked months ahead, so a quote that can start next week deserves a few extra questions. Check the builder carries public liability insurance, ask for addresses of recent extensions you can look at from the street, and agree a staged payment schedule tied to completed work rather than large sums up front. A sensible contingency is 10 to 15 per cent of the build cost, and on older Preston housing stock we would lean towards the higher end.
A small extension of around 15 square metres typically costs £26,000 to £36,000 for the basic build in the Preston area. Add kitchen or bathroom fit-out, glazing upgrades and professional fees on top, so a finished project often lands between £35,000 and £50,000.
Not always. Many single-storey rear extensions fall under permitted development if they stay within national size limits, though building regulations approval is required in every case. If your house is in a conservation area or has had previous extensions, check with Preston City Council before committing to drawings.
A typical single-storey extension takes 10 to 14 weeks on site, and a two-storey extension usually takes 14 to 20 weeks. Allow another two to three months beforehand for design, approvals and booking a builder in.
Tell us about your project. John personally reviews every enquiry and replies within the working day.
