Two-storey side extensions in North Yorkshire

What a two-storey side extension involves

A two-storey side extension is a new two-floor addition built into the space beside your house, often over a driveway or side passage. It typically adds one or two bedrooms upstairs and a utility, study or larger kitchen below, without giving up rear garden.

The main places we list in North Yorkshire are York (YO1), Middlesbrough (TS1), Harrogate (HG1), Scarborough (YO11), Redcar (TS10) and Selby (YO8). We cover the villages in between too.

Guide price in Yorkshire and the Humber

Using our Yorkshire and the Humber rates, a two-storey side extension with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £79,000–£106,500, including VAT. Bigger or more glazed designs cost more per m². We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

Rules in England

In England, a two-storey side extension always needs householder planning permission, because permitted development only allows single-storey extensions beyond a side wall. The fee is £548 (or £575 for applications made from 8 December 2026), and councils should decide within 8 weeks of validation. Expect them to look at set-back, roof height, gaps to the boundary and the effect on neighbours.

The Party Wall etc. Act 1996 applies, so notices may be needed for work on or near a shared wall or boundary.

Getting the design right

Set-down and set-back

Councils usually want a two-storey side extension to look subordinate to the house. Setting the front wall back from the main front and dropping the ridge slightly below the main roof helps it read as an addition, and is often expected in local design guidance.

Side windows, boundaries and gutters

Upstairs windows in the side wall face the neighbour, so they are usually obscure-glazed and fixed, or left out. Building close to the boundary also raises questions about foundations, overhanging gutters and access for maintenance, so we design the eaves and gutter to stay within your land.

How we work in North Yorkshire

1. Look at the house

   We start in North Yorkshire with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.

2. Plans, then approval

   Measured survey, design, then the right approval route for your house. We explain each step before we take it.

3. Detail and price

   Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.

4. On site

   One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Towns we cover in North Yorkshire

• York
• Middlesbrough
• Harrogate
• Scarborough
• Redcar
• Selby
• Guisborough
• Northallerton
• Ripon
• Knaresborough
• Skipton
• Ingleby Greenhow
• Whitby
• Haxby
• Catterick Garrison
• Thirsk

Neighbouring areas

• Two-storey side extensions in County Durham
• Two-storey side extensions in West Yorkshire
• Two-storey side extensions in East Riding of Yorkshire
• Two-storey side extensions in Tyne and Wear

All extension services in North Yorkshire · About two-storey side extensions