Think outside the box and open up to a garden room

Opting for an external addition is cheaper and won’t affect your home’s layout

A friend has just had a garden room built, which she is very excited about. Not only is it providing her with office space, which she can now move out of its current home in her spare bedroom, but it also provides a space for her two teenage children to hang out in with their friends.

The fascinating bit, though, was that for all of the valuable additional space that she was gaining and the fact that it solved several issues she is experiencing in her home, the cost of this structure, with its Tardis-like characteristics, was a fraction of the cost of extending and reconfiguring her house to try and achieve the same result.

This is because opting for an external addition like my friend’s one doesn’t directly impact on the existing layout of your home.

Garden rooms start at €11,000 for a fully-finished 10 sq m (108 sq ft) space. Building costs have gone up considerably in the last 12 months and the average cost of adding extra floor space to your home is now €1,800-€2,000 per sq m, depending on your choice of finishes. That means a 10 sq m extension will start at €18,000 for the build element alone before any extra costs that might be incurred reconfiguring the existing house to work with the new addition.


Another advantage of going for this kind of addition is that there is no impact on your home while the works are ongoing. Anyone who has had any kind of building work done appreciates the amount of upheaval that even the smallest of jobs causes – so this is not to be underestimated.

"A garden room takes on average two weeks to build, and is done without any disruption to the family or their home," says John Sherry of "With over 50 per cent of our projects having restricted access, it makes more sense for us to construct our gardenrooms on site. This allows us to move our materials through side entrances with ease."

The garden rooms are heated by an inverter heater. They generate heat but also act as an air conditioner in the summer. They come with their own fuseboard. A standard electrical package includes six to seven double sockets, smoke alarm, outside socket, internal and external spotlights and TV point as standard.
"We also organise for an electric armoured cable connection back to the main fuseboard in the home," says Sherry.

Conversion costs

These kinds of rooms are ideal for hobby or workout spaces too. We had another client who, rather than converting his attic space, opted for a garden room for use as a studio and music room. The attic conversion was to cost €30,000 and, on weighing up the practicalities, having a space separate to the house was the better and more cost effective option.

Another popular use for these spaces is as utility rooms – they provide space for storage, and hanging out clothes to dry all year round.

Of course you don’t have to sit within the 10 sq m footprint and most companies offer larger versions and some customisation features. I saw a fabulous version of a garden room designed by an architect for a Formula 1 driver which he referred to as a leisure pavilion. It was a beautiful glass and cedar structure that housed a swimming pool, workout space, sauna, changing areas, and a one-bed, one-bath apartment upstairs.

Garden rooms won’t suit everyone but if a separation from the main house is an advantage – be it for working from home, exercise, or independent space for older children – then they can be the perfect solution.

Denise O’Connor is an architect and design consultant