Do I Need Planning Permission? A Simple Guide for Homeowners in Dublin

Murtada Almohsen

Do I Need Planning Permission?

A Simple Guide for Homeowners in Dublin

One of the most common questions we get at BAYT is:

“Do I need planning permission for this?”

If you’re thinking about building an extension, converting your attic, adding a porch or a garden room, it’s important to know where you stand legally. Planning rules in Ireland are fairly clear, but the details do matter, and small changes to your property can mean the difference between needing permission or not.

As a design and build company based in Dublin, we help our clients navigate these rules from day one, so you avoid delays, rejections, or issues down the line.

Here’s a clear breakdown:

When You Usually DON'T Need Planning Permission (Exempted Development)

In many cases, you can carry out small works to your house under exempted development rules, meaning you don’t need to apply for planning permission, as long as the works meet certain criteria.

Rear Extensions (Single Storey)

You can build a rear extension without planning permission if:

The total area (new + any previous extensions) is under 40m²
It’s not higher than the original house
It’s at the back of the house only
It doesn’t reduce private open space to less than 25m²
It maintains certain distances from boundaries and windows don’t overlook neighbours unreasonably

⚠️ Note: If the house has been previously extended, the 40m² includes all extensions combined.

Attic Conversions (Without Dormer)

You don’t need planning permission to convert your attic if:

There’s no change to the roof profile (i.e., no dormer or roof lift)
Velux-style rooflights face the rear or side, not the front
The room is for non-habitable use (e.g., storage, study) or complies with Building Regulations for habitable space (head height, fire escape, insulation)

✅ You can insulate, floor, and fit rooflights under exemption rules, but if you’re adding a large dormer or front-facing roof alteration, you do need permission.

Porches

A porch to the front is exempt if:

It’s under 2m² in area
It doesn’t block sightlines onto the road
It doesn’t go over 2m high if within 2m of a boundary

Larger porches do require planning.

Driveways & Vehicle Access

You generally don’t need planning to create or widen a driveway, but:

You must apply separately to respective city council for a vehicle access licence
You must apply to lower the kerb
Surface water must not flow onto the footpath or road

When You DO Need Planning Permission

You’ll need full planning permission if you’re proposing any of the following:

A two-storey extension
A dormer (especially front-facing or large rear ones)
Side extensions that face the street or exceed exempted limits
Changing the roof shape or ridge height
A garden room or studio over 25m²
Converting a home into separate units or bedsits
Works to protected structures or in an Architectural Conservation Area (ACA)

Conservation & Special Areas

In some areas of Dublin, like Clontarf, Phibsborough, Rathmines, and parts of Dublin 8, your property may be in an Architectural Conservation Area (ACA). In these zones, even exempt works may not be allowed without planning.

We always check zoning, ACA designations, and site history before advising on exemptions.

What If I Go Ahead Without Planning?

Doing work that requires planning but doesn’t have it is considered unauthorised development. This can lead to:

Enforcement action from the council
Issues when selling your home
Possible legal penalties

If unsure, it’s best to check early.

Our Advice: Always Confirm Before You Build

Every home is different. Even if something sounds “exempt,” it depends on:

Past extensions
Your garden size
Neighbouring properties
Zoning and conservation rules

At BAYT, we do a planning check at the start of every project. We handle applications for you if needed, and design within exempted limits when possible, saving you time and money.