Ballynahinch · County Down

First-floor extensions in Ballynahinch

Our first-floor extensions service in Ballynahinch covers everything: measured survey, design, planning or permitted development checks, structural design, building control and the build itself.

The basics for Ballynahinch at a glance.

Postcode districts
BT24
County / area
County Down, Northern Ireland
Price region
Northern Ireland
Guide price
£22,000–£32,000 (£1,580–£2,290 per m²)
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
Carryduff (8 miles), Downpatrick (8.9 miles), Lisburn (10 miles)
Distance to Bangor (County Down)
about 20.1 miles
First visit
Free, no obligation

About a first-floor extension

A first-floor extension suits you if your house already has a single-storey extension and you need more space upstairs. You get a structural check of the existing walls and foundations, a design that ties the new floor into the house, the approvals your nation needs, building regulations approval and the build, managed by us and carried out by vetted teams working under S&K.

Ballynahinch sits about 20.1 miles from Bangor (County Down). Closer to home, Carryduff is 8.0 miles away and Downpatrick 8.9 miles.

What it costs in Ballynahinch

Using our Northern Ireland rates, a first-floor extension with 4 m × 3.5 m of new first-floor space (14 m²) comes to about £22,000–£32,000, including VAT. Bigger or more glazed designs cost more per m². Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.

SpecPer m²4 m × 3.5 m of new first-floor space (14 m²)
Essential£1,460–£2,100 per m²£20,500–£29,500
Standard£1,580–£2,290 per m²£22,000–£32,000
Premium£1,900–£2,750 per m²£26,500–£38,500

Planning and building control in Ballynahinch

In Northern Ireland, a first floor over a rear extension can be permitted development if the extension goes no more than 3 m beyond the original rear wall and stays at least 7 m from the rear boundary, with height, materials and roof pitch conditions. Over a side extension, or beyond these limits, a planning application costs £347 per dwelling.

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 Ballynahinch homes

Escape 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 450 mm high, with the bottom no more than 1,100 mm above the floor, unless there is a protected route to the stairs.

Can the existing structure take it?

Many single-storey extensions were built with foundations, walls and lintels sized for one storey. We find out what is there with trial holes and, where available, the original building control drawings. The engineer then decides whether to reuse, strengthen or rebuild parts of the structure.

How we'd run your project

  1. Free site visit

    We visit your home in Ballynahinch, look at the structure, access and boundaries, and talk through what you want the new rooms to do.

  2. Design and approvals

    We draw the extension and check it against the rules for Northern Ireland, then apply for planning permission or a certificate of lawfulness, whichever fits.

  3. Fixed price in writing

    With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.

  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 first-floor extensions in Ballynahinch

How much does a first-floor extension cost in Ballynahinch?

Our guide for Northern Ireland, which covers Ballynahinch, is £1,580–£2,290 per m² including VAT. A typical project with 4 m × 3.5 m of new first-floor space (14 m²) comes to about £22,000–£32,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Do I need planning permission for a first-floor extension in Ballynahinch?

Ballynahinch 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.

Who handles building control for a project in Ballynahinch?

We handle it as part of the project. What's needed in Northern Ireland: building control approval from the local council under the Building Regulations (Northern Ireland), using the Technical Booklets. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

What happens to the room below while the first floor is built?

The old roof is removed, so the room below is exposed for a short period. We fit temporary weather protection, plan the work so the roof comes off only when the new structure is ready, and agree with you which rooms will be out of use and for roughly how long.

Can I build on top of my existing single-storey extension?

Often yes, but only after the structure has been checked. Foundations, walls and lintels built for one storey may not carry two. We dig trial holes, look for the original building control approval and ask the structural engineer to confirm what can stay, what needs strengthening and what must be rebuilt.

Nearby

Other towns near Ballynahinch:

Other extensions in Ballynahinch

All two-storey extension services in Ballynahinch · First-floor extensions across County Down

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

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