Portrush · County Londonderry

Extra bedroom and en-suite extensions in Portrush

Adding an extra bedroom and en-suite extension in Portrush 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 Northern Ireland.

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

Postcode districts
BT56
County / area
County Londonderry, Northern Ireland
Price region
Northern Ireland
Guide price
£49,500–£66,500 (£1,760–£2,380 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 and stays 7 m from the rear boundary.
Nearest towns
Portstewart (2.7 miles), Coleraine (4.4 miles), Ballymoney (10.2 miles)
Distance to Derry
about 29.5 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 Portrush we also work in Portstewart, Coleraine and Ballymoney, and across the rest of County Londonderry. Postcode district in and near Portrush: BT56.

What it costs in Portrush

Using our Northern Ireland 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 £49,500–£66,500 (plus £5,500–£11,000 for the en-suite), including VAT. Bigger or more glazed designs cost more per m². The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.

SpecPer m²A 4 m × 3.5 m footprint on two floors (28 m² of new floor space)
Essential£1,620–£2,190 per m²£45,500–£61,000
Standard£1,760–£2,380 per m²£49,500–£66,500
Premium£2,110–£2,850 per m²£59,000–£80,000

Planning and building control in Portrush

In Northern Ireland, a rear extra bedroom extension can be permitted development within 3 m of the original rear wall and 7 m from the rear boundary. Upper side windows within 15 m of a neighbouring boundary must be obscure-glazed and non-opening. Other designs need a planning application costing £347, plus building control approval.

Approval in Northern Ireland: Planning application for works to a house: £347. Councils aim to decide local applications within an average of 15 weeks; many take longer.

Building control: Building control approval from the local council under the Building Regulations (Northern Ireland), using the Technical Booklets.

Design points for Portrush 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.

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. Start at your house

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

  2. Drawings and permission

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

  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 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 Portrush

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

Our guide for Northern Ireland, which covers Portrush, is £1,760–£2,380 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 £49,500–£66,500 (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.

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 aim to decide local applications within an average of 15 weeks; many take longer), 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.

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

Portrush is in Northern Ireland. It may be permitted development if it goes no more than 3 m beyond the original rear wall and stays 7 m from the rear boundary.

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

Close to Portrush? We work across the area, including:

Other extensions in Portrush

All two-storey extension services in Portrush · Extra bedroom and en-suite extensions across County Londonderry

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

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