Two-storey side extensions in Liverpool
Want to stay in Liverpool but need more space? A two-storey side extension adds floor area on two levels without giving up much garden. Here's what's involved.
The basics for Liverpool at a glance.
- Postcode districts
- L1, L2, L3, L69 and L70
- County / area
- Merseyside, England
- Price region
- North West England
- Guide price
- £82,000–£109,500 (£1,950–£2,610 per m²)
- Approval route
- Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
- Nearest towns
- Kensington (1 mile), Kirkdale (1.6 miles), Birkenhead (1.9 miles)
- First visit
- Free, no obligation
About a two-storey side extension
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.
We cover Liverpool (L1, L2, L3, L69 and L70) and the places around it, including Kensington (1.0 miles), Kirkdale (1.6 miles) and Birkenhead.
What it costs in Liverpool
Guide prices for two-storey side extensions in North West England are around £1,950–£2,610 per m² of new floor space, including VAT. For a typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space), that's roughly £82,000–£109,500. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.
| Spec | Per m² | A 3 m × 7 m footprint on two floors (42 m² of new floor space) |
|---|---|---|
| Essential | £1,790–£2,400 per m² | £75,500–£101,000 |
| Standard | £1,950–£2,610 per m² | £82,000–£109,500 |
| Premium | £2,340–£3,130 per m² | £98,000–£131,500 |
Planning and building regulations in Liverpool
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.
Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.
Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.
Design points for Liverpool homes
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'd run your project
Visit and first ideas
One of our team visits your house in Liverpool, checks the walls, roof and drains, and sketches out options with you.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Liverpool.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Build
Foundations, walls, floor, roof, windows, then first and second fix. We break through into the house as late as we can.
Questions about two-storey side extensions in Liverpool
Do I need planning permission for a two-storey side extension in Liverpool?
Liverpool is in England, so England planning rules apply. Planning permission is needed: in England, permitted development only allows single-storey extensions to the side. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.
How much does a two-storey side extension cost in Liverpool?
Our guide for North West England, which covers Liverpool, is £1,950–£2,610 per m² including VAT. A typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £82,000–£109,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
How long does a two-storey side extension take?
Allow 4 to 8 weeks for survey and design, then the approval period (councils should decide householder applications within 8 weeks of validation), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.
Which postcodes do you cover around Liverpool?
We cover Liverpool (L1, L2, L3, L69 and L70) and nearby places including Kensington, Kirkdale and Birkenhead, plus the rest of Merseyside. The first site visit is free.
Can I build a two-storey side extension over my driveway?
Yes, if the drive is wide enough for a useful room and the council accepts the design. You may lose off-road parking, which some councils weigh up, and the foundations need to suit the ground below. We check parking, drains and meter positions at the free site visit before any drawings are prepared.
Nearby
Nearby towns we cover for two-storey side extensions:
Other extensions in Liverpool
- Rear
- Wraparound
- Part two-storey
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Liverpool · Two-storey side extensions across Merseyside
Want a figure first? Try our guide price tool, then book a free visit to firm it up.