How to build a garden room – from planning permission to materials

Everything you need to know before investing in a garden room
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  • Over the past couple of years, possibly no addition to a home has been as much of a desirable feature than a garden room. Offering space to work, play or host guests, discovering how to build a garden room will give your house so many more possibilities.

    Less intrusive and more affordable than traditional extensions, garden room ideas let you separate off sections of your life. Plus, it’s a natural place to seek quiet, or contain noisier pursuits, like if someones learning anew instrument.

    ‘A garden room can give you the opportunity to create a space outside of your home within the boundaries of your garden,’ says Jamie Wilson, Founder, Life Space Cabins. ‘This may be for a number of reasons; A place to escape to and read a book, a family craft space or simply an additional room to entertain friends. The uses are endless but the opportunity to create a unique space just for you can be hugely exciting.’

    Read on to discover everything you need to know about how to build a garden room.

    What is a garden room?

    Black garden room with wooden decking

    Image credIt: Future PLC/Colin Poole

    By definition, a garden room is a glazed extension with a fully tiled roof. Garden rooms can either be freestanding, which is a popular choice for home offices, or attached to an existing building. ‘More people now choose a garden room rather than looking at conservatory ideas, since their solid roof construction makes them highly suitable for year-round living,’ notes David Salisbury of David Salisbury Joinery.

    The simplest cabin or summer house is similar to a shed, with either shiplap walls and cedar roof shingles or a log-cabin construction. These are usually supplied in pre-fabricated panels and, if you’re a skilled DIYer, you could put one up yourself.

    More advanced garden room designs, with sliding glass doors or a deck, for example, will need to be built on site by a specialist. Once the concrete base or piles are in, installation can take from one day to two weeks.

    How do you plan for a garden room?

    Black garden room with lazing in front of lawn

    Image credit: Modulr Space

    When deciding upon a garden room, think carefully about how you’d like to use the space – and your budget for garden room costs. ‘If you are considering sacrificing some of your garden or outdoor space for a garden room make sure you have really considered how and when you will want to use it,’ advises  Jo van Riemsdijk, Director, Modulr Space. ‘Any garden room should be an extension of your living space as opposed to subsequent to it.’

    Once you know what you want to use the space for, you can start planning the other details. For example, consider how large you want it to be versus how much of your garden square footage you’re willing to sacrifice. ‘Will you want to use the room all year round?,’ adds Jo. ‘If so – you should think about the insulative U value and also how you will heat it when the weather gets cold.’

    Location is one of the first things that should be considered. ‘Where does the sun rise and fall?,’ asks Jamie from Life Space Cabins. ‘Be aware of your family. Don’t build it somewhere which entails a big climb or long walk if Granny is going to be a regular visitor.’

    Avoid positioning the garden room near growing trees, and ensure there’s access for maintenance. You’ll also need to think about access for delivery, though panels could be carried through the house.

    As for securing your garden room, it’s best to fit locks on doors and choose toughened glass. Check that the locks comply with your home insurance requirements. It’s worth considering external lights, a burglar alarm and Venetian blinds to prevent anyone seeing in.

    Next, consider the layout. ‘Think plan versus nooks and alcoves,’ says Jamie. ‘You want to encourage being together whilst maintaining a peaceful place. Think about a large window seat to create a calm solo space without being hidden away. Think about how the space will adapt as your family grows or gets older?’

    Connectivity is also important right from the off. ‘Have a think about how you will connect with each other,’ suggests Jamie. ‘Can you go without the internet or perhaps a cinema screen is the ultimate way your family can spend time together.

    Finally, have fun with designing the garden room. ‘This could be your opportunity to design some really playful elements into a space,’ points out Jamie. ‘Sliding doors, hanging chairs, bookshelf, hammocks or craft table.’

    Do you need planning permission for a garden room?

    Garden with hedge and path leading to garden room

    Image credit: Life Space Cabins

    There isn’t an across the board answer on this one.’ Typically cabins within the domestic curtilage don’t require planning permission or building regulations, as permitted development allows you to build (within strict criteria) without a full planning application,’ points out Jamie from Life Space Cabins. ‘There are some exceptions – if you are within a conservation area; a National Park; near or in the curtilage of a listed building or in an Area of Outstanding Natural Beauty AONB then you will need to acquire full cabin planning permission.’

    ‘A general rule of thumb is that you won’t need planning permission for an outbuilding with a maximum eaves height of 2.5 metres and a maximum roof height of four metres with a dual pitched roof,’ adds Jo from Modulr Space. ‘Even so, a structure that might not require planning consent in one set of circumstances might need it in another. Whatever you are building, it’s always worth consulting your local planning officer first.’

    So while typically if your garden or summer house ideas are away from the house, takes up less than 50% of the garden and is smaller than 15 sq m, you’re unlikely to need planning permission or Building Regulations Approval. Remember that is you intend to have people sleeping there this can affect planning permissions, too. However always check with www.planningportal.gov.uk, and consult your local council’s planning department.

    How close can I build to my neighbours boundary?

    Garden room with open bi-folding doors in front of lavender border

    Image credit: Future PLC/Claire Lloyd-Davies

    How to build a garden room will be impacted by neighbours to some degree. How close you can go varies depending on local restrictions and the height of your new building.

    While you should always check with your local council there are some rule of thumb guidelines to bear in mind. ‘A garden room should always be built with at least half a meter around it in order for the structure to be maintained,’ advises Jo from Modulr Space. ‘If the roof of your garden room goes to the max of 4 meters with a dual pitched roof – your garden room should be at least four meters away from any boundary.’

    Can I use a garden room all year round?

    Wooden garden room on decking by lake

    Image credit: Future PLC/Polly Eltes

    To maximise the potential of your garden build all year round you should look for a design that is well insulated. If your garden room is insulate well and fit double-glazed windows, you’ll be fine to still use it for the colder months. ‘ Look for the U value – the lower the figure – the more effective the insulation,’ advises Jo from Modulr Space.

    An electrician can run a cable from your house to the room to power lights and heating to ensure the space is useable throughout the darker, colder months. Some garden rooms mat also have underfloor heating and thermal glazing systems to minimise heat loss.

    In addition to heating, lighting is important. In some cases, downlighters, sockets and wiring may be pre-installed in the panel walls, too.

    What materials can a garden room be made from?

    Close up of black garden room with open doors

    Image credit: Future PLC/Lizzie Orme

    Garden rooms can be made from all sorts of different materials – both indoors and out. Timber and metal solutions are the most popular for the exterior.

    ‘Think hygge when choosing the right interior materials,’ advises Jamie from Life Space Cabins. ‘Wood creates a lovely welcoming smell and softness to the space. But vinyl flooring is having a comeback with plenty of colours to choose from. It makes a hard wearing choice. For cabin foundations, ground screws can be used instead of a concrete plinth. Cement is energy intensive to produce whereas ground screws are much less disruptive to the earth, allowing the site to be used for other purposes in the future if required.’

    ‘As a general note, ensure timber is responsibly sourced (locally sourced, FSC or PEFC certified, or marked where possible),’ adds Jamie. ‘Avoid using materials that have a larger carbon footprint in favour of alternative UK sources. Don’t be afraid to ask a supplier where materials are sourced from.’

    How to use a garden room?

    Garden room with open sliding doors

    Image credit: Future PLC/Colin Poole

    How you use a garden room depends on the build, as to whether or not you run electrics to a new garden building or simply upgrade the shed.

    For garden office ideas, the primary considerations are internet strength and lighting. Make sure you can do your job safely and with ease, otherwise you’ll never use the space.

    Are you considering using your garden room as a home gym? ‘Talk to your supplier about whether you might need a reinforced flooring system,’ advises Jo from Modulr Space. ‘Some units are created from SIPS panels and a dropped heavy weight on the floor could damage the structure.’

    ‘You should consider head height. Will you be able to use the room as a gym or will you need to go for an increased height if you are tall? Remember that permitted development allows for 2.5 meters in height on a boundary moving to 4 meters at the peak of a roof if the unit is 2 meters away from any boundary.’ Expensive gym equipment can be an investment, so ensure your security is up to scratch.

    For a garden games room you’ll need plenty of space to play table games – L247cm x W153cm for a table tennis table, for example. Make this the main factor when planning the layout and size. Fancy making yours a music room? Look for a specialist company that offers sound-proofing.

    ‘Look for designs and structures that offer longevity and the ability to be used for alternative functions’ says Jo. ‘Ultimately – you get what you pay for with garden rooms. As opposed to a house extension – they offer good value if you pick one that will be around and useful for a long period of time.’

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