Sales of stand alone structures for gardens rocketed during the period after the pandemic lockdowns of 2020 and 2021 as people felt the need to extend their living spaces outside.

Garden buildings, often described as Garden Rooms, provide options for creating a home office, studio, gym, hobby room or just extra living space without costly or disruptive extensions to the main house, so they can be very appealing. There are a number of things to think about when considering one.

Choosing a Garden Room

It sounds obvious, but probably the most important factor is whether the loss of garden space is really what is wanted! In a small garden, perhaps losing space for plants and trees and a pleasant green outlook from downstairs rooms is less desirable.

To check the impact, it can be a good idea to test the parameters of a garden room structure in the space by marking it out. Use bamboo canes cardboard and string to mark out the footprint and corners to give you an idea of the volume the structure may take up. Look carefully at whether it will overshadow areas, what the view to it and from it may be and whether the size you require would be one that needs a bespoke design or can be found ‘off the shelf’.

There are ways of mitigating having a structure in the green space of a garden. A green roof can maintain habitats for those all important pollinators like bees and insects, and it can help reverse the negative impact of a concrete base on surface water drainage. There is also the opportunity to harvest rainwater from the roof of a garden room to water the rest of the garden.

Simple structures that are not insulated, and that may be self-built are an option for lower budgets but these cannot be occupied all year round. Examples would be typical timber summer houses or cabins. Versatile garden rooms tend to be designed to be able to be heated and stay warm all year round. Prices vary depending on the size, type of structure, type of foundation, the connection of utilities, thermal and acoustic insulation requirements, heating and cooling services and how the garden room will be installed and decorated. A higher design specification and requirement for the garden room to be installed by professionals, naturally attracts a higher cost.

Off the shelf versions are supplied by large DIY retail chains and garden centres, while more bespoke designs can be ordered from dedicated garden room specialists, who may also refer to the structures as home offices, garden pods and even expressions like ‘shoffice’ seem to be used! Finding retailers online by using those simple terms in the search engine offers up many local choices – make sure to look for reviews/references for the firm you choose and if you want a completely bespoke design to be constructed for you by a builder or carpenter, get at least three detailed quotes to compare.

It’s really important to look carefully at access to the garden and check in with suppliers to see what kind of access they require for delivery and installation. If there is no direct access to the garden, options for pre-fabricated structures too big to bring through the house will be limited.

Garden Room Designs

There is a wide range of styles for garden rooms, from traditional timber framed and timber clad pitched structures to futuristic glass pods. The prices and designs vary wildly so research is needed to establish which one is right for different gardens and different uses. Examples should be viewed before being ordered whenever possible, and always check reviews.

Garden_Room_2

Image from www.cuckooland.com

For those that want to make an architectural statement there are companies that specialise in unusual structures, and these are often supplied as a complete package, where the deign and installation is all included. For those looking for more traditional looking garden buildings like summerhouses, there are companies that supply these to be self-built or delivered and assembled for you. Contemporary, often more orthogonal structures, can be bought both as DIY and all in one packages. Some examples are included in the images and corresponding links in this blog to give ideas about the possibilities for every type of garden space.

 

Foundations and walls

How your garden room is supported in the ground is dependant on factors like the soil conditions and type of structure proposed. Slabs cast in concrete create a firm foundation for larger garden rooms but can have a lot of impact on your garden. Soil needs to be excavated and care must be taken to avoid damage to the root systems of any nearby trees. If they are protected trees with a Tree Preservation Order (TPO), advice must be sought from the local planning authority before work commences. For smaller projects, plinths constructed of masonry such as concrete blocks, bricks, or paving slabs can create a lower impact foundation that can be completely removed and recycled at a later date. A base can also be constructed from timber deck and fixed into the ground with a bearing plate and piles that pin the structure into the ground. There is also a product described as a ‘ground screw’ detailed in one of the links below that looks like a neat and less disruptive way of securing a structure on a timber base into the ground. If you are making the base yourself, ensure it is completely level!

There are a number of risks associated with constructions that need to be either designed out comprehensively by the garden room company, or tackled with some good advice in a self-build project. Air must be able to circulate beneath
the garden room floor to prevent excess

moisture causing fungal attacks or rot, particularly if it is constructed of timber. Where there are uninsulated walls, these need to be able to easily ventilate so no moisture barriers such as polythene sheeting should be used as this could trap moisture inside the structure risking excess humidity that can cause condensation, damp and mould inside. If there is a masonry base, a damp proof course should be included to prevent moisture rising into the structure and in insulated walls a vapour barrier should also be included on the warm side of the insulation within the walls to prevent warm air passing through the fabric of the building to the cold side where it could cause condensation leading to mould and rotting timber within the construction itself. A breather membrane needs to be placed on the cold side of the insulation to allow any moisture that gets in to pass out again.

These cross-section diagrams from www.designingbuildings.co.uk explain where damp proof layers and breather membranes are placed in an insulated timber structure. In each diagram, the external layer is on the left and inside space is to the right:

Garden_Room_4

Planning and other consents

The Planning Portal is the go to place for advice on planning. Garden rooms are regarded as ‘outbuildings’ for planning purposes and these are considered to be ‘permitted development’ i.e. not requiring planning permission, in many cases – but there are notable exceptions. The rules apply to houses and not to flats, and any structures proposed within the curtilage of a listed building or on designated land, such as conservation areas or world heritage sites, require planning permission.

There are also limitations on having self contained sleeping accommodation and businesses without consent. You can make an enquiry to your local planning authority to check whether your garden room falls into these categories. If none of these special circumstances apply, then simple parameters to follow would be a single storey structure with a maximum height of 2.5m, floor area that is no more than half the area of land around the original house, and with no verandas or balconies, though the Planning Portal link below outlines more flexible options.

Services like electrics require building regulations approval – a local building control service can advise on what to include in specific applications. You can find approved inspectors on the Planning Portal too.

Using natural materials like timber in garden rooms can create healthy living spaces that appeal to all the senses. Though there are many things to consider, perhaps the overriding benefit of garden rooms is that they can provide a wonderful opportunity to spend more time outside all year round amongst nature, immersed in natural light and experiencing the elements from a cosy space.

A garden room can be incorporated as part of a wider comprehensive garden design, so speak with a garden designer to make the best of all available space. Your designer will be able to advise on what variety of plants would complement the scale of the garden room and provide the best year round outlook.

References:

Great all round blog including information on VAT: https://gardenroomhub.co.uk

Planning Portal one stop shop for planning guidance: https://www.planningportal.co.uk/permission/common-projects/outbuildings/planning-permission

Which? Guide to choosing a garden room: https://www.which.co.uk/reviews/extensions/article/garden-rooms/how-to-buy-the-best-garden- room-aS5rK1w9B0uF

Unusual luxury garden pods https://www.cuckooland.com/brand/ornate-garden/grande-deluxe-garden-pod

Simple insulated examples https://www.cabinmaster.co.uk/product/garden-rooms

All in one bespoke design and installation company https://swiftorg.co.uk

DIY uninsulated structures https://www.gardenbuildingsdirect.co.uk/summerhouses/picton-summerhouse

The Great British Ground Screw: https://gbgs.co.uk/ground-screw-bases-for-garden-rooms-and-offices/

Designing Buildings: The Construction Wiki https://www.designingbuildings.co.uk/wiki/Breather_membranes_for_buildings

PLEASE NOTE:

None of the companies featured in this article are tried and tested by the author – images from their websites and links to their products are supplied purely as examples of different types of garden rooms, and are not intended as recommendations.