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Building a garden room is a relatively inexpensive way to add space – and it can make a glorious architectural statement.

How to build a garden room

Building a garden room is the ideal option if you don’t have room for the home office, art studio or teenagers’ hangout that would make your life easier. A garden room is often a less expensive solution than an extension, loft conversion, or even moving house. And it’s not just about creating additional floor space. For a home-worker or artist it can offer both physical and mental separation from the house that will allow for more productive, creative thinking.


Size and Planning

‘The first consideration for designing a garden room should be the space that you have available and whether you’re happy to relinquish it,’ says Michelle Lord at Pod Space (0845 519 0406; pod-space.co.uk). ‘As a general rule, permitted development will allow 50 per cent of the garden to be used for outbuildings, but there are several exceptions and additional guidance that needs to be followed.’

To remain within permitted development rules, outbuildings should be no taller than 2.5 metres if they are within two metres of your garden boundary. Usage is a further issue: buildings must be ‘incidental to the enjoyment of the dwelling’ – essentially not a self-contained flat, otherwise it will need planning permission.

Building Regulations also apply in some circumstances, such as if your structure contains sleeping accommodation, or if it is between 15 and 30 square metres and sits within a metre of your boundary.


Off-the-peg options

The market for garden rooms has exploded: firms with a national reach are sharing the market with local companies and architects happy to take on small but special projects. A timber kit is the cheapest option (from around £6,000 for a self-build one, but most firms will construct it for you) and many are also customisable, so you can tweak the dimensions and adjust the position of windows and doors.

There can often be a big difference in specification. Most of the benchmarks of quality are concerned with insulation levels and longevity: look for thick walls (at least 6cm), or even SIPs or cavity walls; double glazing; insulated roofs and floors, and an EPDM (rubber) roof with optional covering of shingles or tiles, as opposed to cheap felt.

If you’re going down the off-the-peg route, be aware that the groundworks, insulation, electrics, and paint finishes are often not included.

How to build a garden room1


Hiring an Architect

If you’re looking for innovation – whether in the external appearance, materials or use of space – an architect is a good bet. ‘An architect can create something original and site specific,’ says David Green, director at Belsize Architects (020 7482 4420; belsizearchitects.com). Green designed a building for one client that was sunken to make it less overlooked, with a copper roof that matched the mesh used on an extension to the main property.



Electricity is a must, even if you’re using your structure only as a casual summerhouse; attractive external lighting can enhance the whole garden. If you want your outdoor room to be usable all year, then aim to provide heating, lighting and plug sockets. Your home’s electricity circuit can be extended to the garden via armoured cables buried in a trench, which can also carry network cabling if you want internet access. Use a qualified electrician to carry out the work.

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Internal Specification

How you fit out your new room will be dictated by its use. Home offices are still the most popular function, suggests Lord, so you might want a built-in desk plus bespoke storage in the same material to streamline the look.

Don’t forget to incorporate some shed space for gardening equipment and bikes. Keep this section separate and tucked to one side or at the back


In Focus: Heating

  • Garden buildings should be usable all year, so some form of heating is vital. Extending a gas central heating system isn’t economically viable unless the structure is very close to your main home – you’re better off investing in insulation.
  • The Under Floor Heating Store (0844 800 3396; theunderfloorheatingstore.com) quotes around £340 for a 200W kit for a 2.5x3m room, including insulation boards and a digital thermostat.
  • An effective renewable solution is an air source heat pump, such as Worcester Bosch’s Greensource, which will cost around £1,500 to £2,000.
  • A wood burner is a good option for bigger rooms; installing one will need to comply with the relevant section of Building Regulations.

Words: Emily Brooks, Photography: Will Pryce

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