Garden Room Frequently Asked Questions

Is it legal to sleep in a garden room? 

Yes, up to 28 days in a temporary structure. If the intention is to provide ancillary accommodation, then either the garden room will require planning permission, or it should be constructed as a mobile home and sited within the domestic curtilage for sleeping. 

How big can a garden room be without planning permission? 

The maximum size of a garden room allowed without planning permission is dictated by the amount of garden space it will occupy. A garden room can occupy up to 50% of the total garden area under permitted development rights. For a garden room beyond this size, you will need to gain additional planning permission. A prima mini office is usually a good choice for smaller gardens.

Click here for the garden room planning guide.

Can you put a toilet in a garden room? 

There are no restrictions on putting a toilet into a garden room in respect of adding the plumbing connections for running water. Connection to sewer systems needs to be carried out by an accredited plumbing technician. 

Do I need planning permission for a garden room? 

For most people, the installation of a garden room won't require a planning application. However, there are controls in place to ensure that buildings constructed (like a 4m x 3m garden office) have a limited impact on the surrounding neighbourhood 

For most properties, these controls are called permitted development rights - These rights define the criteria for buildings you're permitted to construct without making a planning application. 

For properties without permitted development rights or for larger projects exceeding the limits of permitted development (see below) planning permission from the local authority should be granted before work begins. This is a routine practice and we have guided hundreds of customers through the process which shouldn't be seen as a barrier to getting your dream garden room.

Size restrictions 

The garden building will adopt less than 50% of the overall garden, and be less than 30m² in size. 

The garden building will be less than 15m² if within 1m of the boundary. 

Garden buildings at addresses within special planning zones* may be limited to 10m² if positioned closer than 20m to the house. 

Proximity to border 

Garden buildings within 2m of the boundary should be under 2.5m in height. 

Garden buildings more than 2m of the boundary can be up to 4m in height. 


A garden building should be sited behind the house, in the back garden. 

Buildings can also be sited set back and to the side of the house, provided the address is not within a special planning zone*. 

Status of house and garden 

  • Conservation areas 
  • Areas of Outstanding Natural Beauty 
  • National parks 
  • World heritage sites 
  • All of the above zones will have adjusted or limited permitted development rights. Occasionally, addresses in these zones will not have any permitted development rights. Specific information on this will be available from your local authority. 

Listed buildings do not have permitted development rights and garden buildings require listed building consent. 

A building sited in the garden of a flat or apartment building will always require planning permission from the local authority. 

As a planning condition, addresses within some housing developments will not have permitted development rights. These will typically be new-build estates but it is worth reviewing the deeds.

Click here to read the full planning guide.

Check out one of our 3m x 3m proline garden buildings.

What are the building rules for a garden room? 

Garden rooms between 30sq m and 50sqm require part building control if unheated. Buildings over 50sqm will usually require full building control. 

For garden rooms of more than 15sqm and within 1m of a boundary, an appropriate class 0 fire retardant is required for the exterior of the building. 

Do you need to dig foundations for a garden room? 

Garden rooms will typically sit on a level base. Baseworks can either consist of a hard standing, such as paving slabs or a concrete base; alternatively, a timber deckbase can be incorporated onto jackpads or screwpiles which are removable and of low/no environmental impact.

Garden Affairs deckbase

Can I have a kitchen in my garden room? 

A kitchen can be added to a garden room to create a versatile space for entertaining, work, play and occasional overnight stays.  There are no restrictions in respect of adding the plumbing connections for running water and connection to wastewater systems needs to be carried out by properly accredited plumbing technicians. 

What size garden room do I need? 

A 1.8m x 2.4m mini office is quite sufficient for the needs of a single desk worker in a garden room.  Hobby rooms and craft studios for single occupancy tend to need more space and these garden rooms can be up to 5m x 3m.  Home businesses such as therapy rooms can function well with a 3m x 3m garden room.  

For more information on sizing, click here to read our garden room size guide.

What materials should I use for my garden room? 

When constructing a garden room, you should use high-quality, reliable materials that can sustain a long lifespan when subject to all weather conditions.  

Solid timber construction offers a high-performing, reliable and eco-conscious choice for garden rooms. In addition to natural timber, there are synthetic low-maintenance cladding options such as Tricoya (used in the popular Proline range). The type and level of insulation for your garden room will depend on the wall, floor and roof build up, and it is best to seek professional guidance on thermal performance and how to avoid dampness etc.

Proline Garden Room with low-maintenance Tricoya cladding.

How much will my garden room cost? 

Small, well-insulated garden rooms can be installed for less than £8,000. The costs for garden rooms are dependent on the size and type of the building.  Large well insulated high-performance multi-room studios, with full electrics including heating, interior and exterior lights, hot and cold running water, additional deckbase and gazebos can be £25,000 - £35,000. 

For more information on garden room pricing, click here to read our pricing guide.

How long will it take to build my garden room? 

Garden room installations vary in length according to size and complexity.  Pod kits for self-assembly can take an averagely competent DIY enthusiast 3 to 4 days to complete; while professional installers might take 8 hours to install a mini office. It is unlikely that even for the larger garden room projects a team of craftsmen would take more than 4 days. 

How will I heat and cool my garden room? 

The heating for a garden room is an essential part of its design.  The orientation of a building and its windows to the arc of the sun can make an important contribution. 

With a small 2kw heater year-round economic occupation can be enjoyed at a low cost.  The thermal efficiency of modern garden buildings means that it doesn’t take long to heat up the garden room in the morning.  Then, a thermostat can very efficiently maintain a comfortable ambient room temperature of 19-21c throughout the day. 

In summer a well-insulated garden room can simply be kept cool with good ventilation. 

How will I maintain my garden room? 

Some modern garden rooms are very low maintenance.  This will depend upon the cladding and the overall construction system.  Walls of solid timber in log cabins will need periodic treatment and painting to ensure long-lasting performance.  A well-insulated, properly roofed, high-quality modern garden room can be very low maintenance. 

Click here for our garden room maintenance guide.

What are the benefits of having a garden room? 

The benefit of additional space provided by a garden room can offer a sanctuary of peace away from the house and the other occupants (eg spouse, children and pets).  A private secure comfortable garden room is the perfect place for work or leisure or entertaining. 

Garden rooms provide multiple benefits that can evolve, and at any one time, a garden room can be dual purpose such as a parent’s office in the day and kids' gaming room in the evening. 

Increasingly the addition of a garden room adds significant value to a house price. A log cabin can add upwards of £22,000 to your property value according to Click here to read the full article.

Learn More

If you still have unanswered questions about garden rooms, get in touch with the team at Garden Affairs to learn more.

Contact us