Extra bedroom and en-suite extensions in Whittlesey
For an extra bedroom and en-suite extension in Whittlesey, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for Cambridgeshire.
What we'd confirm first for a project in Whittlesey.
- Postcode districts
- PE7
- County / area
- Cambridgeshire, England
- Price region
- East of England
- Guide price
- £57,500–£78,000 (£2,060–£2,780 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
- Peterborough (5.1 miles), March (9.2 miles), Chatteris (10.4 miles)
- Distance to Peterborough
- about 5.1 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 Whittlesey we also work in Peterborough, March and Chatteris, and across the rest of Cambridgeshire. Postcode district in and near Whittlesey: PE7.
What it costs in Whittlesey
Most of the cost of an extra bedroom and en-suite extension is set by its size and specification. For Whittlesey and the rest of the East of England, our guide is £2,060–£2,780 per m² including VAT, so about £57,500–£78,000 (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). Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.
| Spec | Per m² | A 4 m × 3.5 m footprint on two floors (28 m² of new floor space) |
|---|---|---|
| Essential | £1,900–£2,560 per m² | £53,000–£71,500 |
| Standard | £2,060–£2,780 per m² | £57,500–£78,000 |
| Premium | £2,470–£3,340 per m² | £69,000–£93,500 |
Planning and building regulations in Whittlesey
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 Whittlesey homes
Connecting to the landing
The new bedroom must be reached from the existing landing, usually through a new opening in the outside wall or by taking part of an existing bedroom as a corridor. We look at the stairs and landing first, because a poor connection can waste much of the new space.
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
Visit and first ideas
One of our team visits your house in Whittlesey, checks the walls, roof and drains, and sketches out options with you.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
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 Whittlesey
Who handles building regulations for a project in Whittlesey?
We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.
Which postcodes do you cover around Whittlesey?
We cover Whittlesey (PE7) and nearby places including Peterborough, March and Chatteris, plus the rest of Cambridgeshire. The first site visit is free.
Do I need planning permission for an extra bedroom and en-suite extension in Whittlesey?
Whittlesey 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.
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
The same service in neighbouring towns:
Other extensions in Whittlesey
All two-storey extension services in Whittlesey · Extra bedroom and en-suite extensions across Cambridgeshire
Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Whittlesey.