Garage conversions with a room above in County Down

County Down 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.

County Down towns we list: Bangor (County Down) (BT19), Newtownards (BT22), Newry (BT35), Banbridge (BT32), Dundonald (BT16) and Holywood (BT18). Every other address in County Down is covered as well.

Guide price in Northern Ireland

A guide price for County Down: 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%. The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.

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

Infilling the garage door

The garage door opening is usually filled with a new wall and a window, on a new foundation, with brick to match. The new front wall needs a cavity, insulation and a damp-proof course, and the window position should line up with the room above.

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 Down

Visit and first ideas
One of our team visits your house in County Down, checks the walls, roof and drains, and sketches out options with you.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in Northern Ireland before drawing in detail.
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.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Towns we cover in County Down

Garage conversions with a room above in County Down: questions

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

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.

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.

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 I need planning permission in County Down?

County Down 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 Down · About garage conversions with a room above