Garage conversions with a room above in County Antrim

County Antrim at a glance

Nation: Northern Ireland
Price region: Northern Ireland
Postcode areas: BT
Towns covered: 15 listed below, plus surrounding villages
Approval route: Planning permission is needed: permitted development side extensions in Northern Ireland can't be more than 4 m high, which rules out two storeys.
Site visits: Free, no obligation

What a garage conversion with a room above involves

This service suits you if your attached garage is used for storage rather than parking and you need both a ground-floor room and an extra bedroom. You get a structural check of the garage, a design for both floors, the approvals your nation needs, insulation and damp-proofing to modern standards and the build, carried out by vetted teams working under S&K.

Towns in County Antrim include Belfast (BT1), Lisburn (BT10), Newtownabbey (BT36), Castlereagh (BT4), Carrickfergus (BT38) and Ballymena (BT42). If yours isn't listed, we still cover it.

Guide price in Northern Ireland

A guide price for County Antrim: around £27,500–£40,500 (for the room above; converting the garage itself is priced after the survey) for 3 m × 6 m of new first-floor space (18 m²). That works out at £1,540–£2,240 per m² of new floor space, including VAT at 20%. Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

Spec	Per m²	Typical project
Essential	£1,420–£2,060 per m²	£25,500–£37,000
Standard	£1,540–£2,240 per m²	£27,500–£40,500
Premium	£1,850–£2,690 per m²	£33,500–£48,500

Rules in Northern Ireland

In Northern Ireland, a room above a side garage normally needs a planning application, which costs £347 per dwelling, because two-storey permitted development is set out for rear extensions. The garage conversion and the new first floor both need building control approval from the council under the Technical Booklets.

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.

There is no Party Wall Act in Northern Ireland. Shared walls and boundaries are a matter of title and common law, so we agree access and record conditions with neighbours before work starts.

Getting the design right

Foundations and walls

Garage footings are often shallow and the walls are a single skin of brick or block. Carrying a new first floor usually means underpinning or new foundations, and new inner walls or a steel frame. Because the garage is being converted too, this work can be designed once for both floors.

Raising and insulating the floor

Garage floors are usually lower than the house and have no insulation or damp-proof membrane. We raise the floor to meet the house level where possible, with insulation and a membrane, so the converted room is warm and dry and does not have a step down.

How we work in County Antrim

Start at your house
We come to your home in County Antrim, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
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.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
Build it
The new structure goes up first, then we open into the house, finish inside and get the completion certificate.

Towns we cover in County Antrim

Garage conversions with a room above in County Antrim: questions

How much does a garage conversion with a room above cost in County Antrim?

In Northern Ireland our guide is £1,540–£2,240 per m² including VAT, so about £27,500–£40,500 (for the room above; converting the garage itself is priced after the survey) for 3 m × 6 m of new first-floor space (18 m²). Essential and Premium specs move that by roughly 8% down or 20% up.

Does the room above need a fire door if the garage is converted?

Once the garage becomes a habitable room, the fire separation needed between a garage and the house usually falls away. The new bedroom above still needs an escape window or a protected route to the stairs, and smoke alarms. If you keep part of the garage for storage, separation may still be needed, which we confirm with building control.

Is it worth converting the garage at the same time as building above it?

Usually, yes. Building a room above often means upgrading the garage foundations and walls anyway, so converting it at the same time spreads that cost over two rooms. You also have one period of disruption, one set of drawings and one building regulations approval instead of two.

Will losing the garage affect parking?

It can. If the garage counts towards required parking on your estate, the council may look at whether enough off-road spaces remain. Most households in practice park on the drive. We check your title and any planning conditions about the garage at the start.

Will I need planning permission in County Antrim?

County Antrim is in Northern Ireland. Planning permission is needed: permitted development side extensions in Northern Ireland can't be more than 4 m high, which rules out two storeys.

Neighbouring areas

All extension services in County Antrim · About garage conversions with a room above