Planning Exemption
A 45 m² home in the back garden.
Without planning permission.
In April 2026, the Irish Cabinet approved a sweeping planning exemption: homeowners can install a self-contained modular home of up to 45 m² in their back garden without applying for planning permission — and rent it under the Rent-a-Room scheme for up to €14,000 a year, tax-free. This page explains exactly what the exemption covers, who qualifies, and how to use it.
floor area
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A new class of auxiliary dwelling.
Until now, Irish planning rules required homeowners to apply for full planning permission to install any habitable structure in their garden — even a granny flat for a parent or an annex for an adult child. Detached structures were exempt only if they were under 25 m² and non-habitable (sheds, garden offices, storage).
The 2026 exemption introduces a brand-new category called an auxiliary habitable dwelling: a self-contained modular unit of up to 45 m² that can be installed in the back garden of a home without applying for planning permission, provided certain conditions are met.
The change is significant because, for the first time, the exemption explicitly covers full residential use — including sleeping, cooking and bathroom facilities — rather than just incidental garden buildings. Combined with parallel changes to the Rent-a-Room tax scheme, it creates the option of a fully-rented secondary dwelling on the same plot as the family home, generating up to €14,000 per year tax-free.
Six conditions that must be met.
The exemption isn't unlimited. To qualify, the development must satisfy each of the following criteria.
Floor area up to 45 m²
The modular unit must have a total floor area of no more than 45 square metres. Anything larger requires standard planning permission.
Owner-occupier only
The homeowner must be living in the primary dwelling. The exemption isn't available to landlords adding units to investment properties — only to families using their own home.
Minimum 25 m² of garden remaining
After installation, the property must retain at least 25 m² of usable private outdoor space. This rules out tightly-packed urban gardens where a 45 m² unit would consume the entire plot.
Separate entrance
The auxiliary dwelling must have its own entrance, separate from the main house. The occupants enter and exit independently.
Minimum distance from main house
A minimum separation distance between the modular unit and the main dwelling is required. The exact distance will be specified in the final regulations.
Full Building Regulations compliance
Building Regulations still apply in full — covering insulation, structural integrity, fire safety, ventilation, electrics and water. Exemption from planning ≠ exemption from build quality.
€14,000 a year. Tax-free.
Tánaiste and Minister for Finance Simon Harris confirmed that the Rent-a-Room scheme will be extended to cover these new auxiliary dwellings. The Rent-a-Room scheme has been in place for years for spare rooms in the main house — but its extension to detached back-garden units is what makes the modular exemption financially powerful.
Under the scheme, a homeowner can earn up to €14,000 per year in rental income tax-free, provided they continue to live in the main residence. Crucially, this is a hard limit — if you charge more than €14,000 per year, the entire amount is taxable, not just the excess. So a rent of €1,166 a month sits right at the threshold; €1,200 would tip you over.
Three models within the 45 m² limit.
1-Bed Cottage
The flagship exemption-eligible model. Fully self-contained: en-suite double bedroom, open-plan living/kitchen/dining. Flat or gable roof.
20×10ft Shepherds Hut
Compact open-plan studio. Bed, kitchenette, shower room. Designed for one or two — perfect as a self-contained back-garden cabin.
25×14ft Shepherds Hut
Larger two-bedroom hut with double bedroom and bunk room. Sleeps four. Functioning wheels — relocatable if your needs change.
Our 2-Bed Cottage (67 m²) and 3-Bed Cottage (52 m²) sit above the 45 m² threshold and are designed for full residential use with standard planning permission.
Quick answers to common questions.
Is the 45m² exemption in effect right now?
Not yet. The exemption was approved by Cabinet on 21 April 2026 but still requires environmental assessment and approval by both Houses of the Oireachtas before it becomes operative law. Government has indicated the regulations should come into force during 2026.
Can I rent out a 45m² modular home in my back garden?
Yes — under the expanded Rent-a-Room scheme, you can rent out an exemption-eligible modular unit for up to €14,000 per year tax-free, provided you continue to live in the main residence as your principal home. Rent above €14,000 makes the full rental income taxable, not just the excess.
Does the tenant have full tenancy rights?
No. Occupants of Rent-a-Room units are classed as licensees, not tenants under the Residential Tenancies Act. They don't have the same protections (no PRTB registration, no rent pressure zone caps, easier termination). Be honest with prospective occupants about this — it's been raised as a concern by housing advocates.
Do I need Building Regulations approval?
Yes — always. Building Regulations are completely separate from planning. The exemption removes the planning permission step but the unit must still comply with regulations covering insulation, structural integrity, fire safety, ventilation, electrics, and water. All our cottages and shepherds huts are built to meet these standards as a matter of course.
What if my garden is smaller than 25m²?
The exemption requires at least 25 m² of usable garden space to remain after the unit is installed. If your back garden is too small to accommodate both the modular home and the 25 m² remainder, you don't qualify. In that case, full planning permission is the route — which is still possible, just slower and more expensive.
Can I install a modular home as a rental investment?
Not under the exemption alone. The exemption is restricted to owner-occupiers — you must be living in the primary dwelling. Landlords adding units to an investment property need full planning permission. The exemption is designed to help families, not investors.
What's the minimum distance from the main house?
The Cabinet decision references "a minimum distance" but the exact figure will be specified in the final regulations. We'll update this guide as soon as the regulations are published. In the meantime, expect something in the range of 2-3 metres — consistent with other detached structures under Irish planning law.
Will the property value go up?
Generally yes — a fully-built, self-contained modular dwelling adds usable habitable space and rental potential, both of which support the valuation of the principal dwelling. However, the unit can't be sold separately from the main house, so the value is captured at the point you sell the whole property, not as a standalone asset.
How long does it take to install a modular home?
Most of our cottage and hut projects run in weeks rather than months. The unit is factory-built while groundworks happen on-site, then delivered, lifted into place with a crane, and connected to services. On-site installation typically takes one to three days; the total project timeline including factory build is usually 8-12 weeks depending on the model and site complexity.
Can I use the exemption for a home office or studio instead of a residence?
Yes — the exemption explicitly covers habitable use, so a 45 m² unit used as a home office, studio, gym or other auxiliary space is also covered. The exemption is generous in this respect: it doesn't dictate what you have to use the space for, only that it complies with building standards and the rules above.
Ready to put one in your garden?
Tell us about your site, your timeline, and what you'd use the space for. We'll come back with a tailored quote and clear guidance on how the exemption applies to your specific situation.
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