Building & Construction · Essex

Cost of Single Storey Extension in Basildon (2026)

Basildon quotes for single storey extension are landing between £1,945 and £3,455 per m² at the moment. Most jobs take 10–16 weeks. The three things that move the price most around Essex are ground conditions and foundation depth; glazing ratio (bi-folds, roof lights); kitchen refit included.

Typical cost in Basildon +8%
Low £1,945
Typical £2,700
High £3,455
Typical price per m² Last updated 22 April 2026
  • FMB Federation of Master Builders
  • TrustMark Government-endorsed
  • FENSA Glazing installer scheme
  • NHBC Warranty-backed builds

About single storey extension in Basildon

Basildon is a large city of around 187,000 in Essex. The housing is mostly a mix of Victorian terraces, inter-war semi-detached housing and modern new-build estates. That matters: older properties usually mean more pipework, rewiring and retrofit surprises, while newer builds in districts like SS13, SS14, SS15 tend to be quicker jobs with standardised fittings. Local trade prices sit a little above the UK average, which tracks with Essex labour and material costs.

The East of England is a mixed bag. Cambridge and St Albans price up near London; market towns and the Fens are reasonable. If you're outside the main commuter belt, expect a mileage charge baked into the quote for anyone travelling in.

Building jobs are labour-heavy, and materials have moved fast — brick, timber, steel, insulation and board are all 20 to 40 percent up on pre-2022. FMB and TrustMark are your best signposts for a proper builder. On anything bigger than a loft conversion, get a Building Control officer involved from day one; fixing non-compliance later costs a fortune.

Single Storey Extension cost breakdown in Basildon

Basic £1,945 – £2,375

Simple rear extension with standard finish

Standard £2,375 – £2,915

Open-plan kitchen extension with bi-fold doors

Complex £2,915 – £4,320

Wrap-around or glazed extension with lantern roof and structural steels

What affects the price of single storey extension in Basildon?

  • Ground conditions and foundation depth
  • Glazing ratio (bi-folds, roof lights)
  • Kitchen refit included
  • Structural steels and knock-through
  • Planning permission vs PD

Basildon vs the UK average

Basildon sits in the building & construction market at a cost multiplier of 1.08× the UK national average. That puts Basildon single storey extension prices at £1,945–£3,455 versus the UK average of £1,800–£3,200 per m².

Basildon vs UK national average — per m² Basildon £1,945 £3,455 UK average £1,800 £3,200
Typical price range, per m²

Single Storey Extension cost calculator — Basildon

Estimated cost in Basildon
£2,495 – £3,060
per m²

Estimate based on live 2025 UK trade pricing. Always get 3 written quotes before committing.

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What's typically included in a single storey extension quote

  • Foundations and drainage
  • Brick and block shell
  • Roof and glazing
  • First and second fix
  • Plaster and decoration

Frequently asked questions

How much does single storey extension cost in Basildon?

Budget £1,945 to £3,455 per m² for single storey extension in Basildon. Prices here are around 8% more expensive than the UK average. What moves a quote inside that range is mostly building contractor day rates in Essex and the specific material list for your job.

How long does single storey extension take in Basildon?

A straightforward single storey extension job in Basildon runs to 10–16 weeks. You can lose days to things outside the contractor's control — parts on backorder, awkward access, or a firm slotting your job around existing bookings. Ask for a start date and expected finish up front.

What's included in the price of single storey extension in Basildon?

A proper single storey extension quote in Basildon should cover: Foundations and drainage; Brick and block shell; Roof and glazing; First and second fix; Plaster and decoration. If any of those aren't itemised on your quote, push back and ask. A written guarantee with a clear warranty period is reasonable to expect on this kind of work.

Is single storey extension cheaper in Basildon than the UK average?

Single Storey Extension in Basildon runs around 8% more expensive than the UK average. The UK-wide benchmark for this job is £1,800 to £3,200 per m²; Basildon quotes tend to land between £1,945 and £3,455. Handy to know what the average actually looks like before you price round.

Do I need planning permission for single storey extension in Basildon?

Most rear extensions fall under Permitted Development (up to 6m terraced/8m detached with Prior Approval). Side extensions and Article 4 areas require full planning. If the property sits in a conservation area or is listed, ring Essex Council before you book anything in. It's a free call and saves a world of grief later.