Two-storey side extensions in Bedfordshire

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.

Bedfordshire towns we list: Luton (LU1), Bedford (MK40), Dunstable (LU5), Leighton Buzzard (LU7), Ampthill (MK45) and Kempston Hardwick (MK42). Every other address in Bedfordshire is covered as well.

Guide price in the East of England

Expect a two-storey side extension in Bedfordshire to land somewhere around £88,500–£119,000 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Our East of England guide rate is £2,110–£2,830 per m², including VAT. 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

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.

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 Bedfordshire

1. Look at the house

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

2. Get it approved

   Once you're happy with the design we submit it to the council for Bedfordshire and deal with any questions from the planning officer.

3. Detail and price

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

4. Build and hand over

   We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Towns we cover in Bedfordshire

• Luton
• Bedford
• Dunstable
• Leighton Buzzard
• Ampthill
• Kempston Hardwick
• Kempston
• Biggleswade
• Flitwick
• Henlow
• Sandy

Neighbouring areas

• Two-storey side extensions in Hertfordshire
• Two-storey side extensions in Buckinghamshire
• Two-storey side extensions in Northamptonshire
• Two-storey side extensions in Cambridgeshire

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