Braintree · Essex

Extra bedroom and en-suite extensions in Braintree

Adding an extra bedroom and en-suite extension in Braintree gives you two new rooms stacked on one footprint. Here's how we'd approach it, what it typically costs and the rules that apply in England.

Before you start in Braintree, here's what applies.

Postcode districts
CM6, CM7 and CM77
County / area
Essex, 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
Halstead (5.9 miles), Witham (6.6 miles), Chelmsford (10.5 miles)
Distance to Southend-on-Sea
about 24.5 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%.

We cover Braintree (CM6, CM7 and CM77) and the places around it, including Halstead (5.9 miles), Witham (6.6 miles) and Chelmsford.

What it costs in Braintree

Our guide for the East of England is £2,060–£2,780 per m² including VAT. On a project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that puts an extra bedroom and en-suite extension in Braintree at roughly £57,500–£78,000 (plus £5,500–£11,000 for the en-suite). Professional fees for drawings and the structural engineer are listed separately on our prices page.

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 Braintree

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 Braintree 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.

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.

How we'd run your project

  1. Understand the brief

    At your home in Braintree we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.

  2. Drawings and permission

    Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Braintree.

  3. Engineer it

    Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.

  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 Braintree

Which postcodes do you cover around Braintree?

We cover Braintree (CM6, CM7 and CM77) and nearby places including Halstead, Witham and Chelmsford, plus the rest of Essex. The first site visit is free.

Do I need planning permission for an extra bedroom and en-suite extension in Braintree?

Braintree 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 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.

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.

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.

Nearby

Nearby towns we cover for extra bedroom and en-suite extensions:

Other extensions in Braintree

All two-storey extension services in Braintree · Extra bedroom and en-suite extensions across Essex

Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.

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