Irish Planning Guidance
Garden room planning permission in Ireland
Most Modern Garden Rooms are exempt from planning permission. Here’s exactly what the rules say — and how we keep your build within them. We confirm everything during your free site visit.
The headline rule
Build up to 25 m² with no planning permission required.
Provided at least 25 m² of private open space remains to the rear of your home, and the height and boundary rules below are met.
Size & height limits without planning permission
| Rule | Limit in Ireland |
|---|---|
| Maximum garden room floor area | 25 m² (about 270 sq ft) |
| Maximum height, flat or mono-pitch roof | 3 m |
| Maximum height, tiled or slated pitched roof | 4 m |
| Minimum window distance from a boundary | 1 m |
| Private open space remaining behind the house | At least 25 m² |
Garden room planning rules explained
Size limits
You can build a garden room up to 25 m² (270 sq ft) without planning permission, as long as at least 25 m² of private open space remains to the rear of your home.
Height restrictions
A mono- or single-pitch roof can go up to 3m high; a slated or tiled pitched roof up to 4m — measured in line with the planning exemption.
Window placement
Windows can't be placed within 1m of your neighbour's boundary. Positioning glazing thoughtfully keeps you exempt and protects everyone's privacy.
Building to the side
If you build to the side rather than the rear, you'll typically need to screen the structure with fencing or set it back to stay within the rules.
Existing structures
An existing timber or block shed can use up part of your 25 m² exemption — so existing outbuildings need to be counted before you build.
Neighbour courtesy
You don't need a neighbour's permission to build within the exemption, but it's good practice to let them know out of courtesy before work starts.
Rules can vary with your site and local authority, and they do change over time — always confirm your specifics. We check everything against the latest Development & Planning Guidelines and walk you through it on your free site visit. You can also see how it all fits together in our build process and specifications.
Planning Permission FAQ
Do I need planning permission for a garden room in Ireland?
In most cases, no. A garden room used as exempted development doesn't need planning permission, as long as it stays within the size, height and placement rules above.
How big can a garden room be without planning permission?
Up to 25 m² (about 270 sq ft), provided at least 25 m² of private open space remains to the rear of your home.
How high can a garden room be without planning permission?
Up to 3 m for a flat or mono-pitch roof, or up to 4 m for a tiled or slated pitched roof.
Can I sleep in or live in a garden room?
An exempted garden room can't be used as a separate, self-contained dwelling or permanent residence. It's for use incidental to your home — an office, gym, studio or guest room.
Do existing sheds count towards the 25 m²?
Yes. Existing outbuildings such as a shed use up part of your 25 m² exemption, so they need to be counted before you build.
Do I need my neighbour's permission to build a garden room?
No, you don't need a neighbour's permission to build within the exemption. Windows must be at least 1 m from a shared boundary, and it's good practice to let neighbours know as a courtesy.
Rooms we build within the rules
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