Can I Build Without Planning Permission? The 25m² Rule Explained

Can I Build Without Planning Permission? The 25m² Rule Explained

One of the most common questions we get at our Dublin showroom is: "Do I need planning permission for this cabin?"

While we always recommend checking with your local council, here is the general rule for Ireland:

The Exemption (Class 3)

You can generally build a structure up to 25 square metres (approx 270 sq ft) in your garden without planning permission, provided:

• It is not used for living/sleeping (e.g., it is a home office, gym, or play area).
• You leave at least 25 sq metres of garden space remaining.
• The height does not exceed 4m (tiled roof) or 3m (flat roof).
• It is located behind the building line of the house.

When Do You Need Permission?

If you plan to sleep in the cabin or use it as a permanent residence (like a granny flat), you will need planning permission, regardless of size.

At MF Timber House, we provide full architectural drawings to help you with your application if needed.

Keywords: planning permission Ireland, log cabin permit, 25sqm exemption, garden room rules