Covering Northallerton
Northallerton sits 30 miles north-west of York, with Darlington 14 miles to the north and Thornaby-on-Tees 14 miles to the north.
Homes in Yorkshire and the Humber
Stone-built terraces are typical of many West Yorkshire towns, while red brick dominates in Hull and much of South Yorkshire, so matching materials is a big part of designing an extension here.
What is a double-storey extension?
Two-storey work has to sit comfortably with the house and the neighbours, so most of the design effort goes into the roofline, window positions and how the new first floor connects to the landing. We handle the planning application, the structural design and the building control process, then build, roof and finish both floors.
- Measured survey, design and planning drawings
- Householder planning application
- Foundations, steelwork, brick and block walls, roof
How much does a double-storey extension cost in Northallerton?
What double-storey extensions typically cost. These are guide ranges; the written quote for your house replaces them.
| Double-storey extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £2,400 to £2,900 per m² |
| Good specification | £2,900 to £3,400 per m² |
| High specification | £3,400 to £3,850 per m² |
What approvals does a double-storey extension need in England?
Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.
Two-storey rear extensions can sometimes be permitted development in England (no more than 3 m deep, at least 7 m from the rear boundary, roof pitch to match), but most two-storey and all two-storey side extensions need householder planning permission.
What can affect a double-storey extension?
- Neighbours’ light is assessed using the 45-degree guide many councils use.
- The new roof is tied into the old one, so roof tiles and ridge details need to match.
From first call to completion
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
Your questions answered
How much does a two-storey extension cost?
Typically about £2,400 to £3,850 per square metre of new floor area including VAT. A 40 m² extension across two floors is often around £100,000 to £150,000 depending on specification.
Does a two-storey extension need planning permission?
Usually yes. In England some two-storey rear extensions are permitted development, but side extensions over one storey always need planning permission.
Who deals with the council for a project in Northallerton?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Double-storey extensions near Northallerton
- Double-storey extensions in Darlington
- Double-storey extensions in Thornaby-on-Tees
- Double-storey extensions in Stockton-on-Tees
- Double-storey extensions in Billingham
Learn more about double-storey extensions, or see every project we cover in Northallerton.

