Extra bedroom and en-suite extensions in Wellingborough
We plan and build extra bedroom and en-suite extensions for homeowners in Wellingborough and nearby. Every project starts with a free visit and a design stage priced in writing before any work begins.
What we'd confirm first for a project in Wellingborough.
- Postcode districts
- NN8 and NN29
- County / area
- Northamptonshire, England
- Price region
- East Midlands
- Guide price
- £55,000–£74,000 (£1,960–£2,650 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
- Rushden (4 miles), Kettering (6.7 miles), Northampton (8.8 miles)
- Distance to Northampton
- about 8.8 miles
- First visit
- Free, no obligation
About an extra bedroom and en-suite extension
An extra bedroom and en-suite extension is a two-storey extension planned around a new double bedroom with its own shower room on the first floor, with a ground-floor room below. It is one of the most effective ways to add space for a growing family. Nationwide's 2025 research linked adding a double bedroom and bathroom to a three-bed, one-bathroom house with value gains of up to 24%.
Wellingborough sits about 8.8 miles from Northampton. Closer to home, Rushden is 4.0 miles away and Kettering 6.7 miles.
What it costs in Wellingborough
In the East Midlands, which includes Wellingborough, we'd expect an extra bedroom and en-suite extension to cost around £55,000–£74,000 (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), or £1,960–£2,650 per m² including VAT. Design fees, structural calculations and approval fees are separate and listed on our prices page.
| Spec | Per m² | A 4 m × 3.5 m footprint on two floors (28 m² of new floor space) |
|---|---|---|
| Essential | £1,800–£2,430 per m² | £50,500–£68,000 |
| Standard | £1,960–£2,650 per m² | £55,000–£74,000 |
| Premium | £2,350–£3,180 per m² | £66,000–£89,000 |
Planning and building regulations in Wellingborough
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 Wellingborough homes
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.
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.
How we'd run your project
Free site visit
We visit your home in Wellingborough, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Engineer it
Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.
Questions about extra bedroom and en-suite extensions in Wellingborough
Do I need planning permission for an extra bedroom and en-suite extension in Wellingborough?
Wellingborough 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.
Which postcodes do you cover around Wellingborough?
We cover Wellingborough (NN8 and NN29) and nearby places including Rushden, Kettering and Northampton, plus the rest of Northamptonshire. The first site visit is free.
How much does an extra bedroom and en-suite extension cost in Wellingborough?
Our guide for the East Midlands, which covers Wellingborough, is £1,960–£2,650 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 £55,000–£74,000 (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.
How big should a new double bedroom be?
There is no legal minimum size for a bedroom in a house you own, so the test is whether it works. A comfortable double needs room for the bed with space to walk round it, wardrobes and a door that opens freely. We draw furniture on the plans so you can judge the space before anything is built.
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.
Nearby
Close to Wellingborough? We work across the area, including:
Other extensions in Wellingborough
All two-storey extension services in Wellingborough · Extra bedroom and en-suite extensions across Northamptonshire
Want a figure first? Try our guide price tool, then book a free visit to firm it up.