Gilwern · Powys

Extra bedroom and en-suite extensions in Gilwern

Adding an extra bedroom and en-suite extension in Gilwern 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 Wales.

The basics for Gilwern at a glance.

Postcode districts
NP8
County / area
Powys, Wales
Price region
Wales
Guide price
£51,500–£69,500 (£1,840–£2,480 per m²), plus £5,500–£11,000 for the en-suite
Approval route
It may be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor 10.5 m from the rear boundary.
Nearest towns
Abergavenny (3.3 miles), Blaenavon (3.5 miles), Brynmawr (4.2 miles)
Distance to Newtown
about 48.6 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.

Around Gilwern we also work in Abergavenny, Blaenavon and Brynmawr, and across the rest of Powys. Postcode district in and near Gilwern: NP8.

What it costs in Gilwern

Using our Wales 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 £51,500–£69,500 (plus £5,500–£11,000 for the en-suite), including VAT. Bigger or more glazed designs cost more per m². 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£1,690–£2,290 per m²£47,500–£64,000
Standard£1,840–£2,480 per m²£51,500–£69,500
Premium£2,210–£2,980 per m²£62,000–£83,500

Planning and building regulations in Gilwern

In Wales, an extra bedroom at the rear can be permitted development if the first floor goes no more than 3 m beyond the original rear wall and stays 10.5 m from the rear boundary. A two-storey side extension can also qualify if it is 10.5 m from the side boundary, set back 1 m and adds no more than 50% width. Otherwise the fee is £585.

Approval in Wales: Householder planning application: £585. Councils normally decide householder applications within 8 weeks.

Building regulations: Building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency).

Design points for Gilwern 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 Gilwern we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.

  2. Choose the approval route

    Some designs fit permitted development, most need a householder application. We decide which applies in Wales before drawing in detail.

  3. Structure and building control

    A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.

  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 Gilwern

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

Our guide for Wales, which covers Gilwern, is £1,840–£2,480 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 £51,500–£69,500 (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 Gilwern?

We handle it as part of the project. What's needed in Wales: building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency). We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

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

Gilwern is in Wales, so Wales planning rules apply. It may be permitted development if the ground floor goes no more than 4 m and the first floor no more than 3 m beyond the original rear wall, with the first floor 10.5 m from the rear boundary. 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.

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

We also cover places near Gilwern, including:

Other extensions in Gilwern

All two-storey extension services in Gilwern · Extra bedroom and en-suite extensions across Powys

Book a free site visit in Gilwern and we'll tell you what's possible, what approvals you need and what the design stage would cost.

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