Garden Room in Ireland — Cost, Planning, and When It Beats an Extension
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Garden room: €8,000–€25,000 installed. Under 25 m² is exempt from planning. A home office, gym, or playroom for a fraction of an extension.
Garden room in Ireland: €8,000–€25,000 installed (typically 10–25 m²). Under 25 m² is exempt from planning (Schedule 2, Class 3 of the Planning Regulations). Over 25 m² needs full planning permission. Uses: home office (most common), gym, playroom, art studio, teenager's retreat, granny flat (with restrictions on overnight use). Cheaper than an extension (€2,500–€3,800/m²) and faster to install (2–4 weeks). Best for sites with a flat garden and a clear sightline to the house. Most modern garden rooms are timber-frame with EWI, double-glazed windows, and a heat pump or electric heater.
When this matters most
You're considering a garden room (home office, gym, etc.).
When this doesn't apply
You've already extended the house.
Sources
Planning and Development Regulations 2001, Schedule 2, Class 3. https://www.irishstatutebook.ie/
Frequently asked questions
How much does a garden room cost in Ireland?
€8,000–€25,000 installed (10–25 m²). Under 25 m² is exempt from planning. Most common use: home office. Cheaper than an extension and faster to install.
Do I need planning permission for a garden room in Ireland?
Under 25 m²: exempt from planning (Schedule 2, Class 3). Over 25 m²: full planning permission required. The garden room must be for domestic use, not as a separate dwelling.
What can I use a garden room for?
Home office, gym, playroom, art studio, teenager's retreat, granny flat (with restrictions). Cannot be used as a separate dwelling without change-of-use planning.
When this matters most
You're considering a garden room (home office, gym, etc.).
When this doesn't apply
You've already extended the house.
Where to go next
Branch into
Adjacent decisions at the same stage.
Watch out for
Common mistakes, hidden costs, gotchas.
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