Estiquote

Local costs · South West · September 2026

How much does an extension cost in North Devon?

A mid-range 25 m² single-storey extension in North Devon costs about £65,500 to £81,000 including VAT, or £2,600 to £3,200 per m² at South West prices. North Devon charges £896 for building control on a 10 to 40 m² extension (full plans, including VAT): 7% above the typical council (£840). With design, a structural engineer, building control and a 15% contingency, budget £81,500 to £105,000.

By Estiquote · Prices reviewed · Council fees from North Devon's published schedule · How we calculate

Work out your project in North Devon

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Typical prices in North Devon

Mid-range finish, South West prices, including VAT. The budget adds design and engineering fees, North Devon's building control charge and a 15% contingency.
ProjectBuilding workBudget to plan for
Single-storey extension, 25 m²£65,500 to £81,000£81,500 to £105,000
Double-storey extension, 40 m²£95,000 to £120,000£116,000 to £152,000
Dormer loft conversion, 30 m²£58,500 to £72,500£73,000 to £93,000
Kitchen, medium£9,200 to £16,300£10,600 to £18,800
Bathroom refit£6,100 to £9,200£7,100 to £10,600

Building prices in South West run about 4% above the UK average outside London. Kitchens and bathrooms vary less from place to place than extensions and lofts.

Building control fees in North Devon

North Devon council charges including VAT (plan and inspection combined)
WorkCharge
Extension up to 10 m² (full plans)£759
Extension 10 to 40 m² (full plans)£896
Larger extension, 40-60 m² (full plans)£1,074
Extension 10 to 40 m² (building notice)£896
Loft conversion up to 40 m²£896
Garage conversion£508

North Devon charges £896 for building control on a 10 to 40 m² extension (full plans, including VAT): 7% above the typical council (£840). Source: North Devon's building control charges, 1 April 2026 (3% rise). Inc VAT ("VAT inclusive").

Private approved inspectors set their own prices and are often competitive, so it is worth asking one or two for a quote as well. See how North Devon compares with every council we checked.

Notes on North Devon's schedule

Shared schedule: nmd Building Control (Mid Devon and North Devon). Same fee for full plans and building notice. Bands: single-storey ext/loft <=15 m2; up to two-storey ext <=40 m2; 40-60 m2. Loft figure is loft >15 m2.

Planning

If your extension needs planning permission, a householder application in England costs £548. Many single-storey rear extensions are permitted development and need no application, and a lawful development certificate (£274) confirms it.

Other councils in South West

Building control for a 10 to 40 m² extension:

Questions people ask

How much does an extension cost in North Devon?

A mid-range 25 m² single-storey extension in North Devon costs about £65,500 to £81,000 including VAT for the building work, or £2,600 to £3,200 per m², based on South West prices reviewed in September 2026. With fees and a 15% contingency, budget £81,500 to £105,000.

How much is building control in North Devon?

North Devon charges £896 (including VAT) for a 10 to 40 m² extension (full plans), according to its published schedule (1 April 2026 (3% rise)).

How much does a loft conversion cost in North Devon?

A mid-range 30 m² dormer loft conversion in North Devon costs about £58,500 to £72,500 including VAT for the building work, and about £73,000 to £93,000 with fees and a 15% contingency.

Before you get quotes