Some garden housing units must be registered with the RTB, but others are exempt and do not need to be registered.
There are different rules for:
If a garden housing unit that was already in place before 27 July 2026 is rented out, the landlord must still register the tenancy with the RTB. This applies to self-contained units with a separate entrance to the main house.
The tenancy will be protected under the Residential Tenancies Act. This includes:
If a unit was in place in a garden before 27 July 2026 but it is only rented for the first time after this date, the landlord must still register the tenancy with the RTB.
From 27 July 2026, homeowners can now add a separate housing unit to their back garden without planning permission. If the owner rents this unit, it will not come under the RTB’s remit. They do not need to register it with the RTB.
The unit must be added in line with strict rules set out in the Planning and Development (Exempted Development) Act of 2000) (No. 3) Regulations 2026 SI340 of 2026:
The RTB does not decide if a unit meets planning requirements or qualifies for a planning exemption. Landlords and tenants should contact their local authority first for guidance on whether a unit qualifies for a planning exemption.
The RTB can only take enforcement action for an unregistered tenancy if a local authority has confirmed the unit did not qualify for a planning exemption. When we investigate if a garden housing unit should be registered with the RTB, we may request a copy of the exemption notice given to the planning authority. Local authorities can also share details on planning exemption notices with the RTB.
If an owner adds a new self-contained garden housing unit from 27 July 2026 without a valid planning exemption, they must still register the tenancy with the RTB. This includes any unit added to a garden that is not the owner’s main home.
The RTB does not decide if a unit meets planning requirements or qualifies for a planning exemption.
The RTB can only take enforcement action for an unregistered tenancy if a local authority has confirmed the unit was added from 27 July 2026 and did not qualify for a planning exemption. To report a suspected planning breach, you can write to your local authority’s Planning Enforcement Section.
The best way to report an unregistered tenancy to the RTB is through our Report a landlord webform. If we have evidence to confirm there is an unregistered tenancy, we will take enforcement action which can include:
When we investigate if a garden housing unit should be registered with the RTB, we can request a copy of the exemption notice given to the planning authority. The RTB can also ask local authorities to share information on planning exemption notices through existing data sharing agreements.
If a garden unit is rented but did not qualify for a planning exemption, the owner must:
The landlord could also face penalties for failure to register that include criminal prosecution or a civil investigation and a sanction of up to €15,000.
Where a tenancy should have been registered, the tenant is protected under the Residential Tenancies Act even if the tenancy is not registered. Their protections under rental law include:
If a unit was in place in a garden before 27 July 2026 but it is only rented for the first time after this date, the landlord must still register the tenancy with the RTB. This applies to self-contained units with a separate entrance to the main house.
A unit that qualifies for a planning exemption and that does not need to register with the RTB must be constructed, erected or placed in the homeowner’s back garden after 27 July 2026. It must be placed in the back garden of a house that is the owner’s main home.
The owner must have notified the planning authority at least 14 days before construction began or 14 days before a modular home is erected.
The rules apply to all fixed garden housing units from modular homes to permanent buildings constructed in the garden.
