Two-storey side extensions in Cheshire

What a two-storey side extension involves

A two-storey side extension suits a detached or semi-detached house with a side garden, driveway or garage wide enough to build on. You get a design that sits comfortably on the street, a planning application or permitted development check depending on your nation, structural design, building regulations approval and the build itself. We manage the whole process, and the work is carried out by vetted teams working under S&K.

The main places we list in Cheshire are Warrington (WA1), Chester (CH2), Crewe (CW1), Ellesmere Port (CH65), Widnes (WA8) and Runcorn (WA6). We cover the villages in between too.

Guide price in North West England

For budgeting in Cheshire, allow around £82,000–£109,500 for a two-storey side extension with a 3 m × 7 m footprint on two floors (42 m² of new floor space). That's based on £1,950–£2,610 per m² including VAT for North West England. Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

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

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.

Avoiding a terracing effect

Where semi-detached houses sit close together, side extensions on neighbouring houses can join up and turn a row of pairs into a terrace. Many councils ask for a gap to the boundary at first floor to stop this, so we check local guidance before fixing the width.

How we work in Cheshire

1. Understand the brief

   At your home in Cheshire we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.

2. Design and approvals

   We draw the extension and check it against the rules for England, then apply for planning permission or a certificate of lawfulness, whichever fits.

3. Price it properly

   Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.

4. Build and sign-off

   Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.

Towns we cover in Cheshire

• Warrington
• Chester
• Crewe
• Ellesmere Port
• Widnes
• Runcorn
• Macclesfield
• Northwich
• Great Sankey
• Winsford
• Congleton
• Wilmslow
• Sandbach
• Nantwich
• Neston (Cheshire)
• Poynton
• Middlewich
• Blacon
• Knutsford
• Lymm

Neighbouring areas

• Two-storey side extensions in Merseyside
• Two-storey side extensions in Greater Manchester
• Two-storey side extensions in Clwyd
• Two-storey side extensions in Staffordshire

All extension services in Cheshire · About two-storey side extensions