Extra bedroom and en-suite extensions in Kirkby
For an extra bedroom and en-suite extension in Kirkby, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for Merseyside.
Kirkby: the key facts for this kind of project.
- Postcode districts
- L32 and L33
- County / area
- Merseyside, England
- Price region
- North West England
- Guide price
- £53,000–£72,000 (£1,900–£2,560 per m²), plus £5,500–£11,000 for the en-suite
- Approval route
- It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission.
- Nearest towns
- Fazakerley (2 miles), Croxteth (2.1 miles), Norris Green (2.8 miles)
- Distance to Liverpool
- about 6 miles
- First visit
- Free, no obligation
About an extra bedroom and en-suite extension
This service suits you if you need another bedroom, or want a main bedroom with its own bathroom, without converting the loft or moving. You get a first-floor layout that connects well to your landing, an en-suite designed for plumbing and ventilation, a useful room downstairs, the approvals your nation needs and the build, managed by us and carried out by vetted teams working under S&K.
Around Kirkby we also work in Fazakerley, Croxteth and Norris Green, and across the rest of Merseyside. Postcode districts in and near Kirkby: L32 and L33.
What it costs in Kirkby
Expect an extra bedroom and en-suite extension in Kirkby to land somewhere around £53,000–£72,000 (plus £5,500–£11,000 for the en-suite) for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). Our North West England guide rate is £1,900–£2,560 per m², including VAT. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.
| Spec | Per m² | A 4 m × 3.5 m footprint on two floors (28 m² of new floor space) |
|---|---|---|
| Essential | £1,750–£2,360 per m² | £49,000–£66,000 |
| Standard | £1,900–£2,560 per m² | £53,000–£72,000 |
| Premium | £2,280–£3,080 per m² | £64,000–£86,000 |
Planning and building regulations in Kirkby
In England, an extra bedroom extension at the rear can be permitted development if it goes no more than 3 m beyond the original rear wall and stays 7 m from the rear boundary. Upper side windows, including en-suite windows, must be obscure-glazed and non-opening below 1.7 m. Side or deeper designs need planning permission, costing £548 (or £575 for applications made from 8 December 2026).
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 Kirkby homes
Escape window and fire safety
A new first-floor bedroom needs an escape window with a clear opening of at least 0.33 m², at least 450 mm wide and high, and the bottom no more than 1,100 mm above the floor, unless there is a protected route to the stairs. We design the windows to meet this.
Planning the en-suite
An en-suite needs a route for the soil pipe to the drains, enough fall for waste water and an extract fan to the outside under Part F. Placing it over the ground-floor utility or near an existing drain keeps pipework short and hidden.
How we'd run your project
Start at your house
We come to your home in Kirkby, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Kirkby.
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 extra bedroom and en-suite extensions in Kirkby
How much does an extra bedroom and en-suite extension cost in Kirkby?
Our guide for North West England, which covers Kirkby, is £1,900–£2,560 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £53,000–£72,000 (plus £5,500–£11,000 for the en-suite). Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Which postcodes do you cover around Kirkby?
We cover Kirkby (L32 and L33) and nearby places including Fazakerley, Croxteth and Norris Green, plus the rest of Merseyside. The first site visit is free.
Do I need planning permission for an extra bedroom and en-suite extension in Kirkby?
Kirkby is in England, so England planning rules apply. It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.
Does an extra bedroom add value to my house?
It usually does, though not always by the full cost. Nationwide's 2025 research found that adding a double bedroom to a two-bed house was linked to about 13% higher value, and a double bedroom and bathroom on a three-bed, one-bathroom house up to 24%. Local ceiling prices still apply.
Can an en-suite go in a room with no window?
Yes. A shower room without a window is allowed, provided it has a mechanical extract fan to the outside that meets Part F. Many people prefer a window for daylight, but if it faces a neighbour it will usually need obscure glass. We plan the extract route early so the duct is hidden.
Nearby
Nearby towns we cover for extra bedroom and en-suite extensions:
Other extensions in Kirkby
All two-storey extension services in Kirkby · Extra bedroom and en-suite extensions across Merseyside
Book a free site visit in Kirkby and we'll tell you what's possible, what approvals you need and what the design stage would cost.