New rules on registration of garden housing units

27 July 2026: New rules on when a garden housing unit must be registered with the Residential Tenancies Board (RTB) take effect from today. Some garden housing units must still be registered, but others added from 27 July 2026 under new planning exemptions will not need to register.  

 The RTB is advising landlords and tenants that there are now different rules for: 

• Units added before 27 July 2026 
• Units added from 27 July 2026 with a planning exemption 
• Units added from 27 July 2026 without a planning exemption  

Units added before 27 July 2026 

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: 

• Rent increases are limited under national rent control rules. 
• Tenants get security of tenure (the right to stay) in the rented property after 6 months. 
• Access to the RTB’s dispute resolution service. 
• Possible RTB enforcement action if the landlord breaches rental law. 

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. 

Units added from 27 July 2026 under new planning exemptions 

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: 

• It must be placed in the back garden of a house that is the owner’s main home.  
• The owner must notify the planning authority they intend to use a planning exemption at least 14 days before work to add the garden unit begins.  
• You can learn more how to qualify for a planning exemption on the Department of Housing, Local Government and Heritage’s website. 

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 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. 

 Units added from 27 July 2026 without a planning exemption 

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. 

Speaking on the new rules, Rosemary Steen, Director of the Residential Tenancies Board said:  

“These changes create a new category of garden housing units that do not come under the RTB’s remit. However, it is important to remember that garden housing units in place before 27 July 2026 must still be registered with the RTB if they are rented out. We urge landlords and tenants not to assume that every garden housing unit is exempt. Taking the time to understand the new rules and, where required, to register the tenancy with the RTB is vital to ensure compliance with rental law.” 

 Common questions [accordion on page] 

How can I report a suspected unregistered tenancy to the RTB? 

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: 

• Issuing a fixed penalty notice 

• Criminal prosecution 

• A formal investigation which can result in a sanction of up to €15,000  

 

How will the RTB know when a unit was added to a garden? 

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. 

 

What happens if a garden unit is rented out but it is later found not to qualify for a planning exemption? 

If a garden unit is rented but did not qualify for a planning exemption, the owner must: 

 

• Register all past and current tenancies in the property with the RTB. 

• Pay late fees for all past and current registrations. 

 

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: 

• Their rent increases are limited under national rent control rules. Their landlord may also have to repay any overpaid rent for illegal rent increases. 

• They get security of tenure (the right to stay) in the rented property after 6 months. Their tenancy start date is the date they moved into the unregistered tenancy. 

• They can access the RTB’s dispute resolution service. 

 

What if a unit was in place before 27 July 2026 but it is only rented for the first time after this date? 

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. 

 

What does ‘added to’ or ‘in place’ in the garden mean? 

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. 

 

What types of garden housing units does the planning exemption apply to?  

The rules apply to all fixed garden housing units from modular homes to permanent buildings constructed in the garden.