Peterborough · Cambridgeshire

Extra bedroom and en-suite extensions in Peterborough

Want to stay in Peterborough but need more space? An extra bedroom and en-suite extension adds floor area on two levels without giving up much garden. Here's what's involved.

Useful details for planning an extra bedroom and en-suite extension in Peterborough.

Postcode districts
PE1, PE2, PE3, PE4 and PE5
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
Whittlesey (5.1 miles), Market Deeping (7.7 miles), Stamford (11.2 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.

We cover postcode districts PE1, PE2, PE3, PE4 and PE5 in and around Peterborough, along with neighbouring Whittlesey, Market Deeping and Stamford.

What it costs in Peterborough

Guide prices for extra bedroom and en-suite extensions in the East of England are around £2,060–£2,780 per m² of new floor space, including VAT. For a typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that's roughly £57,500–£78,000 (plus £5,500–£11,000 for the en-suite). Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

SpecPer m²A 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 Peterborough

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 Peterborough 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.

Sound and privacy

Bedrooms above a kitchen or family room benefit from an insulated floor to reduce noise. Side-facing upstairs windows usually have to be obscure-glazed, so we place the main bedroom window to the rear and the en-suite window to the side where possible.

How we'd run your project

  1. Start at your house

    We come to your home in Peterborough, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.

  2. Drawings, then consent

    We draw the scheme, check it against the rules in England, and take it through the right consent with the council.

  3. Technical design

    We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.

  4. Build and sign-off

    Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.

Questions about extra bedroom and en-suite extensions in Peterborough

How long does an extra bedroom and en-suite 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.

How much does an extra bedroom and en-suite extension cost in Peterborough?

Our guide for the East of England, which covers Peterborough, is £2,060–£2,780 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 £57,500–£78,000 (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.

Who handles building regulations for a project in Peterborough?

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.

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.

What goes on the ground floor below a new bedroom?

Whatever suits you: a bigger kitchen, a family room, a study, a utility or a downstairs shower room. The ground floor usually costs about the same whatever it is used for, apart from kitchen units and bathroom fittings, which are priced separately.

Nearby

The same service in neighbouring towns:

Other extensions in Peterborough

All two-storey extension services in Peterborough · Extra bedroom and en-suite extensions across Cambridgeshire

The quickest next step is a visit. We'll look at your house in Peterborough and give you an honest view of the options.

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