Written by Garden rooms have become increasingly popular across Ireland as homeowners look for additional space without extending or moving home. Since July, 2026 and with the new planning regulations coming into effect, it is now possible to build a garden room with the intention of renting it out, however, there are additional planning, building and tax issues you need to consider.
Garden room planning and size conditions
Size Limits: Standalone, self-contained liveable garden homes or cabins must measure between 32 and 45 square metres to qualify for residential rental use under the updated exemptions. Smaller non-habitable rooms (up to 30 m²) are restricted to incidental uses like home offices or gyms and cannot be used for standard habitation.
Owner-Occupancy: The main residential house on the property must remain owner-occupied.No Separate Sale: The garden unit cannot be sold independently or separated from the main property title.
Garden Space: You must retain at least 25 square metres of private open garden space after the structure is built.
Building and Rental Standards
Building Regulations: The unit must fully comply with Irish Building Regulations, covering fire safety, structural safety, ventilation, insulation, drainage, and a valid BER (Building Energy Rating) energy certificate.
Tax Relief: Qualifying long-term arrangements may benefit from the Rent-a-Room Relief Scheme, allowing homeowners to earn up to €14,000 tax-free per year. Keep proper records of rental income and allowable expenses and obtain tax advice where necessary.
Rental Restrictions: You cannot use the garden room for short-term holiday or tourist lettings without separate planning permissions.
Registration Rules: Depending on when and how the unit was established, check current guidelines via the Residential Tenancies Board (RTB) to see if your specific garden housing unit configuration requires formal tenancy registration prior to letting it out.
Before undertaking any type of building works, alterations or additions to your property, always consult the relevant planning authorities and council departments prior to commencing works.