Local costs · North East · September 2026

How much does an extension cost in Northumberland?

Q: How much is building control in Northumberland?

Northumberland charges £780 (including VAT) for a 10 to 40 m² extension (full plans), according to its published schedule (Scheme of charges November 2025).

Q: How much does a loft conversion cost in Northumberland?

A mid-range 30 m² dormer loft conversion in Northumberland costs about £49,500 to £61,000 including VAT for the building work, and about £62,500 to £80,500 with fees and a 15% contingency.

A mid-range 25 m² single-storey extension in Northumberland costs about £55,500 to £68,500 including VAT, or £2,200 to £2,700 per m² at North East prices. Northumberland charges £780 for building control on a 10 to 40 m² extension (full plans, including VAT): 7% below the typical council (£840). With design, a structural engineer, building control and a 15% contingency, budget £69,500 to £90,500.

By Estiquote · Prices reviewed 25 September 2026 · Council fees from Northumberland's published schedule · How we calculate

Work out your project in Northumberland

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Typical prices in Northumberland

Mid-range finish, North East prices, including VAT. The budget adds design and engineering fees, Northumberland's building control charge and a 15% contingency.
Project	Building work	Budget to plan for
Single-storey extension, 25 m²	£55,500 to £68,500	£69,500 to £90,500
Double-storey extension, 40 m²	£80,500 to £101,000	£99,500 to £131,000
Dormer loft conversion, 30 m²	£49,500 to £61,000	£62,500 to £80,500
Kitchen, medium	£8,500 to £15,000	£9,700 to £17,300
Bathroom refit	£5,600 to £8,400	£6,400 to £9,600

Building prices in North East run about 12% below the UK average outside London. Kitchens and bathrooms vary less from place to place than extensions and lofts.

Building control fees in Northumberland

Northumberland council charges including VAT (plan and inspection combined)
Work	Charge
Extension up to 10 m² (full plans)	£780
Extension 10 to 40 m² (full plans)	£780
Larger extension, 30-50 m² (full plans)	£960
Extension 10 to 40 m² (building notice)	£780
Loft conversion up to 40 m²	Not published
Garage conversion	£660

Northumberland charges £780 for building control on a 10 to 40 m² extension (full plans, including VAT): 7% below the typical council (£840). Source: Northumberland's building control charges, Scheme of charges November 2025. Inc VAT total column.

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 Northumberland compares with every council we checked.

Notes on Northumberland's schedule

Own scheme. Single charge (inspection included; building notice same). Bands <30 / 30-50 m2 cover extensions, lofts and garages, so 10-40 figure is the <30 band (30-50 m2 is 960); loft left blank because a 40 m2 loft straddles the bands.

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 North East

Building control for a 10 to 40 m² extension:

Questions people ask