Sudbury (Greater London) · Greater London

Extra bedroom and en-suite extensions in Sudbury (Greater London)

Want to stay in Sudbury (Greater London) 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.

Quick reference for homeowners in Sudbury (Greater London).

Postcode districts
HA0
County / area
Greater London, England
Price region
London
Guide price
£67,000–£90,500 (£2,400–£3,240 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
Brent (0.9 miles), Wembley (1.2 miles), Harrow on the Hill (1.2 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%.

Around Sudbury (Greater London) we also work in Brent, Wembley and Harrow on the Hill, and across the rest of Greater London. Postcode district in and near Sudbury (Greater London): HA0.

What it costs in Sudbury (Greater London)

Using our London rates, an extra bedroom and en-suite extension with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £67,000–£90,500 (plus £5,500–£11,000 for the en-suite), including VAT. Bigger or more glazed designs cost more per m². We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

SpecPer m²A 4 m × 3.5 m footprint on two floors (28 m² of new floor space)
Essential£2,210–£2,980 per m²£62,000–£83,500
Standard£2,400–£3,240 per m²£67,000–£90,500
Premium£2,880–£3,890 per m²£80,500–£109,000

Planning and building regulations in Sudbury (Greater London)

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 Sudbury (Greater London) 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.

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. Look at the house

    We start in Sudbury (Greater London) with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.

  2. Plans, then approval

    Measured survey, design, then the right approval route for your house. We explain each step before we take it.

  3. Price it properly

    Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.

  4. Build it

    The new structure goes up first, then we open into the house, finish inside and get the completion certificate.

Questions about extra bedroom and en-suite extensions in Sudbury (Greater London)

Do I need planning permission for an extra bedroom and en-suite extension in Sudbury (Greater London)?

Sudbury (Greater London) 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 much does an extra bedroom and en-suite extension cost in Sudbury (Greater London)?

Our guide for London, which covers Sudbury (Greater London), is £2,400–£3,240 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 £67,000–£90,500 (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 Sudbury (Greater London)?

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.

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.

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

We also cover places near Sudbury (Greater London), including:

Other extensions in Sudbury (Greater London)

All two-storey extension services in Sudbury (Greater London) · Extra bedroom and en-suite extensions across Greater London

Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Sudbury (Greater London).

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