What a kitchen extension costs in Bristol in 2026

The figures below come from the 31 extension quotes we wrote between January and June 2026. They’re for single-storey rear and side-return extensions on Victorian, Edwardian and 1930s houses, and they include VAT at 20 percent.

The total

A 20 m² kitchen extension, including the kitchen itself, came to between £85,000 and £130,000. The middle of that range was £104,000. Per square metre of new floor, the building work alone was £3,100 to £3,900.

Where the money goes

• Foundations, drainage, walls and roof structure: £34,000 to £46,000

• Steel beams and the opening into the existing house: £6,000 to £11,000

• Glazing (doors and a glass roof or rooflights): £12,000 to £30,000

• Electrics, heating and underfloor heating: £7,000 to £10,000

• Plastering, flooring and decorating: £8,000 to £12,000

• The kitchen, fitted, without appliances: £15,000 to £40,000

Fees before the build

• Drawings and structural calculations: £1,800 to £3,400

• Planning application (£528 in 2025) or lawful development certificate (£264)

• Building Control: £1,100 to £1,600

• Party wall surveyors, if a neighbour appoints one: £1,000 to £1,800 per neighbour

• Build-over agreement with Wessex Water, if needed: about £500

What makes it go up

Glazing is the biggest variable. A frameless glass roof and steel-framed doors cost twice as much as rooflights and aluminium sliders. The second is the ground: clay soil near trees, common in Westbury-on-Trym and Henleaze, can mean deeper foundations, which add £4,000 to £9,000. The third is what we find when the back wall comes out, usually old drains in the wrong place.

We include a contingency line of 5 percent in every extension quote. On the extensions we finished in 2025, an average of 3.1 percent of it was used.