Garage conversion planning permission in Ireland

Do you need planning permission to convert a garage?

Class 1 in Part 1 of Schedule 2 to the Planning and Development Regulations 2001 covers two things. One is a new extension to the rear of a house. The other is the conversion, for use as part of the house, of any garage, store, shed or similar structure attached to the rear or to the side of the house.

So the answer depends on the garage.

• Attached to the rear or side of the house: can be exempt if it meets the conditions.
• Detached from the house: not named in Class 1. Treat it as needing permission unless the council confirms otherwise.
• Garage at the front: the class refers to the rear or side. If the garage is at the front, ask the council how it classes it.

When a garage conversion is exempt

Class 1 applies to a conversion in the same way as to an extension. These are the main conditions as amended by S.I. 338 of 2026, from 27 July 2026.

Floor area

• House not extended before: up to 45 square metres.
• Above ground level, terraced or semi-detached house: up to 12 square metres.
• Above ground level, detached house: up to 20 square metres.
• House already extended: the new work plus any extension built after 1 October 1964 must stay within the same limits. This includes extensions that had permission.

If you convert a garage and also build a rear extension, ask the council how it counts the two together.

Windows, height and garden

• Ground-level windows must be at least 1 metre from the boundary they face.
• Windows above ground level must be at least 8 metres from the boundary they face.
• Any part above ground floor must be at least 2 metres from any party boundary.
• Walls and roof cannot be higher than Class 1 allows.
• The work cannot leave less than 25 square metres of private open space within the curtilage of the house.
• The exemption applies to the main house only, not to another detached house in the same grounds.

When you need to apply

Apply for planning permission if any of these is true.

• The garage is detached from the house.
• The conversion would go beyond the floor area or other Class 1 limits.
• A condition of an earlier planning permission requires the garage to stay as a garage. Article 9 removes the exemption if the work breaks a condition.
• The garage or house is an unauthorised structure.
• The new openings or other changes would materially affect the street appearance and fall outside the exemption.

A change of use, such as using a garage as a separate home or for a business, is a different question. A separate dwelling in the back garden has its own rules, covered in the garden room guide.

Special cases

• Protected structures: under section 57 of the 2000 Act, works are exempt only if they do not materially affect the character of the structure. A garage in the grounds of a protected structure may be affected.
• Architectural conservation areas: Article 9 removes the exemption for exterior works that would materially affect the character of the area.
• Natura 2000 and other nature sites: if the work needs an appropriate assessment, it is not exempt.
• Flood risk: Article 9 does not list flood risk as a reason to lose the exemption. Habitable rooms at ground level can be a concern, so check the council’s flood maps.
• Previously extended houses: earlier extensions after 1 October 1964 count towards the limit.

Other rules that still apply

Planning exemption does not replace the Building Regulations. A converted garage needs to meet standards such as insulation, damp-proofing, ventilation and fire safety. A garage floor and walls are not built for living space, so ask a professional what upgrades you need.

Costs and fees

The national fee for planning permission for a conversion of a garage, store or shed into part of a house is €34. Retention permission costs more. Use the planning fee calculator for the exact amount.

Checklist before you start

• Is the garage attached to the rear or side of the house?
• Is the conversion within the floor area limits, counting earlier extensions?
• Are new windows far enough from the boundary they face?
• Will 25 square metres of private garden remain?
• Does any earlier permission put a condition on the garage?
• Is the house free of protected structure, conservation area or nature site rules?
• Have you checked the Building Regulations with a professional?

Next steps

A pre-planning meeting is a good way to check a detached or front-facing garage. Councils offer these meetings under section 247 of the 2000 Act. The advice does not grant permission.

To apply, read how to apply. If the garage was converted without permission, see retention permission. You can also read about a house extension and browse local planning applications.

The law is changing

The Planning and Development Act 2024 is being brought into force in stages. The July 2026 changes to Class 1 were made under the 2000 Act. Check the Department of Housing’s website for which parts of the 2024 Act are in force.

Check before you build

Garage conversion rules depend on the exact site, the garage and its planning history. A pre-planning report checks zoning, protected structures and nature sites at an address, so you can see the main limits early. Use the pre-planning report or the planning permission checker. Then confirm with your council.