How Much Does a Single Storey Extension Cost in Burnley?

Typical prices for a single storey extension in Burnley

For a straightforward single storey extension in Burnley and the surrounding areas such as Padiham, Nelson and Rossendale, most homeowners should budget somewhere between £1,800 and £2,600 per square metre for the shell and basic finish. That covers foundations, walls, roof, windows, doors, plastering and first fix electrics and plumbing, but not the kitchen, bathroom fittings or high end flooring.

Put into real numbers, a modest 3m by 4m rear extension of around 12 square metres usually lands between £25,000 and £35,000. A larger 5m by 6m kitchen extension of around 30 square metres tends to fall in the £55,000 to £80,000 bracket once you add a decent kitchen and bifold doors. Lancashire labour rates are lower than Manchester or Cheshire, which is why these figures sit below most national averages you will read online.

• Small side return or utility extension (8 to 10 sq m): roughly £18,000 to £26,000
• Standard rear extension (12 to 18 sq m): roughly £25,000 to £42,000
• Large open plan kitchen extension (25 to 35 sq m): roughly £50,000 to £85,000

What pushes the price up or down

The biggest variable is the ground. A lot of Burnley housing is Victorian and Edwardian terraced or semi detached stock built on clay, and some areas near the river Brun and Calder have made ground or old drainage runs. If Building Control asks for deeper trench foundations or you hit a public sewer needing a build over agreement with United Utilities, expect to add £2,000 to £6,000.

Roof style matters too. A flat roof with a fibreglass or EPDM finish is the cheapest option. A pitched tiled roof that matches your existing slates or concrete tiles looks better and adds value, but adds several thousand pounds in labour and materials. Steelwork for opening up the back wall into an open plan space is another common extra, usually £1,500 to £4,000 depending on span and whether a structural engineer's calculations are needed.

Glazing is where budgets often run away. A standard set of uPVC French doors might cost £1,200 fitted. A three panel aluminium bifold or a large sliding door system can easily be £5,000 to £9,000 before you add roof lanterns or rooflights.

• Foundation depth and drainage: clay, trees and sewers all add cost
• Flat versus pitched roof: pitched typically adds £3,000 to £7,000
• Steel beams and structural engineer fees
• Glazing choice: uPVC versus aluminium, bifolds and roof lanterns
• Kitchen, flooring and finishes: easily 20 to 40 per cent of the total
• Access: tight terraced back yards mean hand digging and skip logistics

Fees and costs that are not in the build price

Your builder's quote usually covers the construction, but there are other costs to plan for. Architectural drawings for a single storey extension in the Burnley area typically cost £800 to £1,800. Structural engineer calculations are around £300 to £700. Building Regulations fees through Burnley Borough Council are roughly £600 to £1,000 for an extension of this size, split between the plan check and inspections.

Many single storey extensions fall under permitted development, so you may not need planning permission if you stay within the size limits (generally up to 3m deep on a semi or terrace, 4m on a detached house, using the standard rules). If you do need a planning application, the fee is currently around £300 for a householder application. Homes in conservation areas such as parts of Worsthorne or Cliviger have tighter rules, so check before you start.

It is sensible to hold back a contingency of around 10 per cent of the build cost. Older Lancashire houses often hide surprises once you open up walls, from unrecorded drains to rotten timbers, and a contingency means these do not derail the project.

How to compare quotes without getting caught out

A low headline price is only useful if you know what it includes. Ask every builder for a written, itemised quote that states whether it covers demolition, skip hire, scaffolding, making good to the existing house, electrics certified under Part P, plastering and decorating. Check whether VAT is included, because a quote that is silent on VAT can jump by 20 per cent at invoice stage.

Ask about the payment schedule too. A reasonable approach is staged payments tied to milestones such as foundations poured, roof on and completion, rather than a large deposit up front. Confirm who is responsible for booking Building Control inspections and that you will receive a completion certificate at the end. That certificate matters when you come to sell the house.

Finally, ask for addresses of recent extensions nearby and go and look at them. A builder who has worked on the same kind of terraced and semi detached properties common across Burnley will know the local ground conditions, the council's inspectors and the typical problems before they crop up.