Build a Home in Your Garden | PlotNua Discoveries

Why This Discovery?

Who is this for?

An adult child who cannot afford to move out, or a parent who would rather be near than far. A carer. A guest room that is really a small home.

This Discovery is for anyone who has already decided they want a building in the garden, and now needs to know whether somebody can live in it.

Still deciding how to create the space?

Four Ways to Get More Space compares extending, converting and building.

Explore: Four Ways to Get More Space →

Looking for a room rather than somewhere to live?

Create an Extra Room covers the everyday garden room.

Explore: Create an Extra Room →

What Changes

What is different once somebody lives there?

A garden room and a home in the garden are two different things. The line between them is somebody sleeping there.

Cross it and a separate set of rules applies. The first thing they do is make the building bigger: a home has a minimum size of 32 m² as well as a maximum of 45 m², where a garden room has only a ceiling.

The rest is about how it is owned, connected and used. The regulations call it an auxiliary dwelling.

Services. Water and wastewater run off the main house.
Ownership. It cannot be sold or subdivided away from the main house.
Time. Fourteen days’ notice before you start, and finished by the end of 2030.

The Rules

What exactly is allowed?

The conditions fall into four groups, and they are set out in the 2026 auxiliary dwelling regulations.

The building

Between 32 m² and 45 m². A minimum as well as a maximum.
45 m² is the ceiling for everything. Sheds and garages already in the garden count towards it. A 12 m² shed leaves 33 m²; more than 13 m² and the 32 m² minimum is out of reach.
Up to 4 m high with a tiled or slated pitched roof. 3 m for any other roof.
Permanent. A caravan or a mobile home does not qualify.
At least 0.6 m from any wall or boundary, and windows at least 0.6 m from the boundary they face.

The garden

25 m² of private open space stays. Reserved for the main house.
No new entrance onto a road. The way in stays as it is.
A way in on foot and by wheelchair, within your own property.
No separate water or wastewater connection. Both run off the main house.
Where there is a septic tank, the building keeps off the percolation area.

How it can be used

Occupied in conjunction with the main house. The regulations’ own words.
Not sold, not subdivided. It stays part of the same property.
No short-term letting.
The main house is your own home. You own it and live there when the work starts.
Not available if the house has already been divided into two.

Before you start, and by when

Fourteen days’ notice to the planning authority, with the address, the Eircode and the reason.
Building Regulations, Building Control and fire safety apply, as they do to any new home. The Department’s guidance sets out what that means.
Started and finished by 31 December 2030.

Two things sit outside these conditions and can change the answer.

A protected structure. If the house is on the council’s protected list, work in its grounds may not be exempt. The council will tell you in writing what would and would not affect its character, and it has twelve weeks to answer. Protected structures — Citizens Information
A conservation area. Extra controls can apply where the work would materially affect the character of the area. The council will confirm whether your address is in one.

Your Garden

Does your garden have room?

Three measurements decide it, and none of them needs a professional. Pace the garden and see what is left.

How much ground it takes. About 5.7 m square at 32 m², or 6 m by 7.5 m at 45 m². Add the 0.6 m gap on every side.
What the house has to keep. The 25 m² of open space is about 5 m by 5 m. On a small garden this is the measurement that decides it, so take it first.
What is already out there. Sheds and garages count towards the 45 m², so measure them before you settle on a size.
Getting to it. There has to be a way in on foot and by wheelchair, inside your own property.

If those four come out in your favour, the next question is your own address.

Frequently Asked Questions

Common questions.

Who can live in it?

The regulations say it must be occupied in conjunction with the main house, and they do not define that phrase. Somebody from your own household — an adult child, a parent, a carer — sits comfortably inside it. Short-term letting is ruled out expressly. Beyond that the position is not settled: the Government has said the tax treatment of these homes will be clarified in the Budget, and we will not guess ahead of it.

What happens if I already have a shed or garage?

It counts. The garden-structure exemption and this one share a 45 m² ceiling, and this one has a 32 m² floor, so anything over 13 m² already built takes the option off the table while it stands. Removing it before work starts should return the allowance, and the council is the one to confirm that.

Do I need a builder, or can I buy one ready-made?

Either. A factory-built or modular home is fine, and the Department expects those systems to be certified. What does not change is that a competent builder and a competent construction professional are needed either way — this is a new home, not a garden building.

When can somebody actually move in?

Not the day the building is finished. A Certificate of Compliance on Completion has to be signed and registered with the Building Control Authority before the home can be occupied. That is the real finish line, and it is worth knowing at the start.

What if my house is protected or in a conservation area?

Either can change the answer. If the house is a protected structure, the council will tell you in writing what would and would not affect its character, and it has twelve weeks to reply. In a conservation area, extra controls can apply. One call to the council settles which applies to you.