New for 2026 · Republic of Ireland
A garden home you’re
allowed to live in — up to 45 m².
Since 27 July 2026, Irish planning rules recognise a new category of exempted development — the Detached Auxiliary Dwelling. A detached, habitable building of 32 m² to 45 m² at the rear of your home, for family use, without a full planning application. The standard garden room exemption also rose from 25 m² to 30 m².
30 m²
Garden room, no permission
45 m²
Auxiliary dwelling, habitable
14 days
Notice to the council
2030
Complete before 31 December
Two exemptions, two different things
These are separate categories in the regulations and they are not interchangeable. A garden room cannot be slept in at any size. An auxiliary dwelling can be, but only because it carries conditions a garden room does not.
Class 3
Garden room
- Size
- Up to 30 m²
- Use
- Non-habitable — no sleeping or living
- Offices, studios, gyms, playrooms, storage
- No notification to the local authority
- Building Regulations application not required
- Maximum 3 m high for a mono-pitch roof
- Retain at least 25 m² of open garden space
- No expiry date on the exemption
Class 3A
Detached Auxiliary Dwelling
- Size
- 32 m² to 45 m²
- Use
- Habitable — can be lived and slept in
- Family use only, occupied with the main house
- 14 days’ written notice to the planning authority
- Built to Building Regulations including fire safety
- Maximum 4 m pitched roof, or 3 m any other roof
- Served by the main house — no separate utilities
- Must be completed before 31 December 2030
Who it is for
Made for multi-generational living
The exemption exists to make better use of land families already own. It is limited to occupation alongside the main house — which is exactly the case most people were already trying to solve.
An adult child at home
A self-contained space with its own front door, on the same site, while a deposit is saved. Independence without the rent.
A parent close by
Level access, no stairs, and family a few steps away rather than a drive away. The alternative to a move nobody wants to make.
A live-in carer
Accommodation on site for the person providing care, without converting rooms in the main house or losing privacy on either side.
A returning family member
A place to land after time abroad or a change in circumstances, without the household absorbing the pressure indefinitely.
Built to the spec a dwelling actually needs
Built to the standard a dwelling needs
A Class 3A dwelling must satisfy the Building Regulations, including Part B fire safety. That is a materially higher bar than a garden room has ever had to meet, and it rules out a large share of what is sold as a garden building in Ireland.
Galvanised steel frame
Every Sprout Pod is built on a galvanised steel frame rather than timber. It does not warp, rot or absorb moisture, and it carries a 25-year structural warranty in a climate that is unkind to timber.
A-rated insulation as standard
Continuous insulation around the frame achieves a u-value of 0.18 W/m²K. For a building somebody actually lives in year-round, running cost is not a specification detail — it is the whole experience.
Made in Co. Louth
Fabricated in our own workshop, delivered and installed by our own team. One company carries the design, the build standard and the handover.
How it works, step by step
- 01
Quote and site assessment
We measure the usable area once the 25 m² of retained garden and the 0.6 m boundary setbacks are taken out, and tell you plainly which exemption your site can carry — or whether you need a planning application instead.
- 02
Design to the exemption
The dwelling is designed to sit inside the Class 3A conditions: floor area between 32 m² and 45 m², height, setbacks, window positions, access and services all resolved before anything is fabricated.
- 03
The 14-day notice
We prepare the written notification to your local planning authority using the template set out in the regulations, and it is lodged at least 14 days before work commences.
- 04
Build, deliver and complete
Fabrication off site, installation on site, and handover — with the completion date kept comfortably inside the 31 December 2030 deadline the exemption sets.
Auxiliary dwelling questions answered
- What is a Detached Auxiliary Dwelling (Class 3A)?
- It is a new exemption introduced on 27 July 2026 that allows a detached, habitable dwelling of 32–45 m² to the rear of your home — for family use, such as an adult child, a parent or a live-in carer — without a full planning application. It is linked to the main house's services and can only be used alongside the main home. It cannot be sold, subdivided or short-term let separately.
- What conditions apply to a Detached Auxiliary Dwelling?
- It must be 32–45 m² (counting any existing garden structures towards the 45 m² cap), used only in conjunction with the main house, built to Building Regulations including fire safety, served by the main house's water and wastewater, and kept at least 0.6 m from any boundary. You must give the local planning authority at least 14 days' written notice before starting, retain at least 25 m² of private garden, and the main house must be your sole or main residence. The exemption is time-limited and the works must be completed before 31 December 2030.
- Do I have to tell the council before building a Class 3A dwelling?
- Yes. For a Class 3A Detached Auxiliary Dwelling (and for a Class 1A subdivision) you must notify your local planning authority at least 14 days before work commences, using the notification template in the regulations. It is not a planning application, but it is mandatory. We can help you prepare it.
- Does the Detached Auxiliary Dwelling exemption expire?
- Yes. The Class 3A exemption is time-bound — the dwelling must be completed before 31 December 2030 to rely on it. The standard 30 m² garden room exemption is not time-limited.
The 30 m² garden room exemption and the six criteria that go with it are set out in full on our planning page.
Northern Ireland
These changes apply in the Republic of Ireland only
The Detached Auxiliary Dwelling exemption amends Irish planning law. Northern Ireland continues to operate under the General Permitted Development Order (GPDO) 2015, with its own curtilage, height and footprint tests. We serve Northern Ireland and can advise on the GPDO conditions that apply to your site.
The information on this page is provided as general guidance only and does not constitute legal advice. Planning regulations can change and may vary based on your specific location and property type. Always verify current rules with your local planning authority before proceeding.