Extra bedroom and en-suite extensions in Poole

Poole: the key facts for this kind of project.

Postcode districts: BH15 and BH20
County / area: Dorset, England
Price region: South West 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: Parkstone (2 miles), Canford Heath (2.6 miles), Broadstone (3 miles)
Distance to Bournemouth: about 4.6 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.

Poole sits about 4.6 miles from Bournemouth. Closer to home, Parkstone is 2.0 miles away and Canford Heath 2.6 miles.

What it costs in Poole

Expect an extra bedroom and en-suite extension in Poole to land somewhere around £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). Our South West England guide rate is £2,060–£2,780 per m², including VAT. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

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 Poole

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 Poole homes

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.

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.

How we'd run your project

Visit and first ideas
One of our team visits your house in Poole, checks the walls, roof and drains, and sketches out options with you.
Design and approvals
We draw the extension and check it against the rules for England, then apply for planning permission or a certificate of lawfulness, whichever fits.
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 Poole

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

Our guide for South West England, which covers Poole, 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.

Which postcodes do you cover around Poole?

We cover Poole (BH15 and BH20) and nearby places including Parkstone, Canford Heath and Broadstone, plus the rest of Dorset. The first site visit is free.

Who handles building regulations for a project in Poole?

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.

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.

Can an en-suite go in a room with no window?

Yes. A shower room without a window is allowed, provided it has a mechanical extract fan to the outside that meets Part F. Many people prefer a window for daylight, but if it faces a neighbour it will usually need obscure glass. We plan the extract route early so the duct is hidden.

Nearby

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

Other extensions in Poole

All two-storey extension services in Poole · Extra bedroom and en-suite extensions across Dorset

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