Planning Permission

Most Garden Rooms don’t require permission.

They are classed as outbuildings and are allowed under permitted development as long as certain rules are followed.

You may not have permitted building rights if:

• Your home is a listed building
• Your home is in a designated area (eg a National Park, area of outstanding natural beauty (AONB), conservation area or World Heritage Site)

If you are not sure, check with your local planning office. Flats and maisonettes don’t have permitted development rights. If you live in a listed building or your home is in a designated area such as a national park, you will need planning permission.

The rules regarding permitted development and your garden room are:

• The garden room must not be at the front of your home.
• The total area of all extensions, sheds and outbuildings including the proposed garden room – must not cover more than 50% of the total area of land around your house.
• The garden room must be single story and less than 3 meters high (4 metres with a dual pitched roof). If its within 2 metres of your boundary, the maximum height is 2.5 metres.
• The eaves of the garden room must be no more than 2.5 metres above ground.
• The garden room does not have a veranda, balcony or raised platform.
• The garden room is not self-contained living accommodation.

Building Regulations are about how a structure is designed, built and insulated. Having the right certificates is important, as they’ll be needed if you sell your house.

However Building Regulations don’t usually apply to outbuildings, as long as:

• It’s not attached to your main home
• the floor area is less than 15 sq m
• it doesn’t include sleeping accommodation

If the floor area is between 15sq m and 30sq m, you still don’t usually have to apply for Building Regulations approval, as long as there's no sleeping accommodation and it’s more than 1 metre from your boundary and is made of non-combustible materials.

It will need to comply with Building Regulations if you ever plan to sleep in it or use it as a guest bedroom.

Electrics in your garden room will need to comply with part P of the Building Regulations. For example, if you have a separate consumer unit in your garden room you’ll need to get a qualified electrician to connect it to your mains supply. They will test that the system is safe and issue a certificate showing that it meets the relevant Building Regulations.

You may need planning permission for your proposed garden room if you intend to use it for activities that you would usually do in your main home, such as showering or cooking.

To have a cold water supply to your garden room you’ll need new plumbing installed. This involves two sets of pipes – one to bring fresh water and one to remove waste water.

For fresh water you will need a connection to your mains water in your house. Your waste water pipe may be able to connect to an existing drain. If this isn’t possible, you might need a pump to move the waste water to an outside drain.

If you’re hoping to have hot water, small hot-water heaters are an option. They can be installed under a sink and provide about 7-10 litres of hot water.

Fitting a toilet will probably require a macerator to reduce waste to a pulp. It will also need to be connected it to a soil pipe to take waste to the main sewer.