A Guide to Planning Laws for Garden Rooms

At Concept Modular Homes, we understand that adding a stylish, fully functional space to your property should be simple, not stressful. One of the most common questions we’re asked is:

“Will I need planning permission for my garden room?”

The good news? In most cases - you won’t.

Thanks to Irish planning regulations, homeowners can build a garden room of up to 25 square metres without applying for planning permission, so long as specific conditions are met. This opens the door to beautiful home offices, gyms, guest rooms, creative studios, and more, all without the delays and costs of the formal planning process.

Let’s break it down.

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When is Planning Permission Not Required?

“The Planning & Development Act (Exempted Development Regulations) allows Irish homeowners to build certain structures on their property without needing full planning permission, including garden rooms. To qualify, the garden room must meet the below criteria.

1. Size Limit

Your garden room must not exceed 25 sqm (approx. 268 sq ft).To visualise this: a typical living room in a semi-detached house is 15–18 sqm, and a small double bedroom is about 9–12 sqm, so 25 sqm gives you generous space to work with.

2. Location on Property

Your structure must be positioned to the rear of the main dwelling and cannot be placed in front of the house. This requirement ensures that the structure does not interfere with the streetscape or alter the character of the property’s frontage.

3. Height Restrictions

• Max height of 4 metres if the garden room has a pitched roof
• Max height of 3 metres for flat-roofed structures

4. Garden Space

You must retain at least 25 sqm of private open garden space after the structure is built - ensuring you still have room to enjoy your outdoor area.

5. No Permanent Living Use

The garden room cannot be used as a permanent residence or rental unit. It must serve an ancillary function - such as an office, gym, studio, or occasional guest room, that supports life in the main house.

Other Exemptions to Consider

Planning exemptions may not apply if your home is:

• In a conservation area
• A protected or listed building
• Located near protected landmarks or scenic views
• On a flood plain
• Under Architectural Heritage protection

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The above is our understanding of the current planning exemptions applicable to garden rooms in Ireland. At Concept Modular Homes, we build strictly within the permitted planning parameters.

Please note: It is ultimately the responsibility of the homeowner to ensure their project complies with planning regulations. We strongly encourage you to familiarise yourself with the exemption criteria or consult your local planning authority if you are unsure about your eligibility.

And of course - if you need help navigating the process, our team is here to support you.

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