We here at Adrian Hassett Auctioneers have seen garden rooms move from a novelty to one of the most sought-after features in Irish homes. A dedicated home office at the end of the garden, a gym, a studio or a quiet space for teenagers can add real lifestyle appeal. But not every garden room is what it seems on paper, and some come with planning or compliance questions that can catch buyers out. Before you make an offer, here is what you should check.
Is it exempt from planning, or did it need permission?
Many garden rooms are built under the planning exemptions for structures in the rear garden of a house, such as sheds, stores, home offices and gyms. From 27 July 2026, the maximum floor area for these structures increased from 25 to 30 square metres. That exemption comes with conditions, though. They cover matters such as the structure's position, its height and the amount of rear garden that must be left free, and the total includes any other sheds or outbuildings already on site.
Timing matters too. A garden room built before July 2026 would have needed to meet the rules in place when it was built, so a 28 square metre structure that went up in 2024 may have required planning permission at the time. Ask the seller when it was constructed and whether permission was sought. If there is any doubt, your solicitor may ask for an opinion from an architect or engineer, and the local council can issue a Section 5 declaration confirming whether a structure is exempt.
How is it actually being used?
This is the question many buyers overlook. The standard exemption covers structures used for purposes incidental to the enjoyment of the house, such as a home office or hobby room. It does not cover using the space as somewhere to live or sleep. A garden room with a bed, a shower and a kitchenette, marketed as a guest suite or granny flat, is a very different proposition.
There is now a separate exemption for a detached auxiliary dwelling in the rear garden of a house, linked to the services of the main home, with a floor area of between 32 and 45 square metres. It has its own conditions, and the planning authority must be notified at least 14 days before work begins. If a property is being marketed with a self-contained garden unit, ask for evidence that it was built under the right exemption or with full planning permission, and that the notification was made where required.
Business use can also raise questions. Working from home on your laptop is one thing, but a garden room regularly visited by clients or used by employees could amount to a change of use, so take advice if you plan to run a business from it.
Does it comply with Building Regulations and fire safety rules?
Being exempt from planning does not mean being exempt from regulation. Building and Fire Regulations continue to apply, including stricter requirements for any structure used as a habitable dwelling. Ask whether the garden room was designed and built by a reputable supplier, and request any warranties or certificates.
Electrics deserve particular attention. Garden rooms usually need a dedicated supply from the main house, and the work should have been completed by a Registered Electrical Contractor, who can provide a completion certificate. Your surveyor can check for obvious warning signs, but the paperwork gives you far greater confidence.
Is it well built?
A good garden room should be as comfortable in January as it is in July. Look at the foundations, check for damp, soft flooring or condensation, and ask about insulation, glazing and heating. Inspect the roof covering and gutters, and make sure rainwater drains away properly rather than pooling against the structure or flowing towards a neighbour's property. If there is a toilet or sink, ask how the waste is connected, as this can be complex and costly to put right if done poorly.
What is included in the sale?
Some garden rooms are modular buildings that can, in theory, be dismantled and moved. Never assume one is included. Make sure your solicitor confirms in the contract that the garden room, its fittings and any equipment you expect to stay are part of the sale. Check too whether any supplier warranty can be transferred to you.
Finally, speak to your insurer. A garden room may need to be specifically included in your home insurance, and expensive office or gym equipment may require additional cover.
Tips for sellers
If your home has a garden room, gather the details before going to market, including the build date, floor area, supplier, warranties and electrical certificates. Describe the space accurately in your listing and avoid calling it a bedroom or living accommodation unless it has the permissions to match. Clear, honest information builds buyer confidence and helps avoid last-minute questions from solicitors.
The bottom line
A garden room can be a wonderful asset, adding space, flexibility and appeal. Just make sure the one you are buying is properly permitted, safely built and clearly included in the sale, so it remains a selling point rather than a problem when you eventually move on.
If you would like to discuss buying or selling a property, contact us on 0871303206 or email sales@adrianhassett.com or visit adrianhassett.com.
Disclaimer: This article is based on publicly available information and is intended for general guidance only. While every effort has been made to ensure accuracy at the time of publication, details may change and errors may occur. This content does not constitute financial, legal or professional advice. Readers should seek appropriate professional guidance before making decisions. Neither the publisher nor the authors accept liability for any loss arising from reliance on this material.
