Do you need planning permission for a garden room? Not if you meet these criteria, say the pros

If you want some additional space at home, but don't want to extend or convert, then adding a garden room might be the ideal solution. But do you need planning permission for a garden room, or can you build one without?

Ultimately, whether or not you need planning permission will depend on the size and scope of your garden room ideas and where you live.

To help, we've spoken to leading garden room experts about the rules that apply projects like this, and the circumstances when you might need to submit a planning application.

Do I need planning permission for a garden room?

In most cases, you won't need to submit a formal planning application when building a garden room, as they tend to be classed as Permitted Development, provided specific criteria are met.

Becky Harper, Planning Team Leader at Green Retreats, says: ’What’s great about garden rooms is they rarely require planning permission as they are classed as ‘outbuildings’ and, as such, fall within permitted development rights.'

But strict criteria will need to be met.

• Area of outbuildings cannot exceed 50% of total land surrounding the house
• Can be no higher than 4m (pitched roof), 3m (flat roof) or 2.5m (if within 2m of a boundary)
• Cannot be used for business purposes that involve public visits or as self-contained living space
• No verandas, balconies or raised platforms (a platform must not exceed 0.3 metres in height)
• Must sit behind the front wall of the house (cannot be in the front garden).

In order to be classed as Permitted Development, the total area of all outbuildings (including the garden room) cannot exceed more than 50% of the original land surrounding the house. This means that if you have already extended, or already have multiple sheds, you might need to get planning permission for your garden room.

There are size requirements you'd need to meet too. The maximum height for a garden room with a dual pitched roof is four metres, and it's three metres for a flat roof. If you want to locate your garden room within two metres of your property's boundary, then the height cannot exceed 2.5m.

Whether or not you need planning permission will also depend on what you plan on using the garden room for.

Jenny Davis, Head of Marketing for Forest Garden, says: 'Other exceptions where homeowners may need planning permission are if they wanted to use the building independently to the main home, such as for commercial purposes, including running your own business, or as a self-contained property.'

She adds: 'When it comes to amenities, planning rules vary so if you plan to install any plumbing or electricity to the building, do consult your local authority.'

As with any Permitted Development rights, if you live in a designated zone like a National Park, conservation area or Area of Outstanding Natural Beauty, or a listed building, then you're rights may be restricted or removed, so you'll need to apply for planning permission.

It's always best to check with your local planning authority before investing in a garden room to make sure you are compliant with the policies in your area.

Does a garden room need to meet Building Regulations?

Depending on the size and use of the garden room, you don't normally need Building Regulations sign off.

If the floor area is less than 30 square metres, it's not used for sleeping accommodation and it's not within one metre of a boundary, then you should be find to proceed without approval from building control, but do double check before you invest.

FAQs

Can my neighbour object to me building a garden room?

Provided your garden room meets the requirements laid out under Permitted Development, or you have secured planning permission, then you're neighbour can't stop you from adding it.

However, it's always a good idea to keep your neighbour up to date with your plans to alleviate any worries they may have and to maintain your relationship.

What happens if you ignore the planning rules when building a garden room?

If you build a garden room that falls outside of the scope of Permitted Development and you don't obtain planning permission, then you could find yourself facing enforcement action from the local planning authority, which can mean making changes to the garden room, or even having to demolish it altogether.

To avoid that, you may be able to apply for retrospective planning permission. However this can be stressful, and there is no guarantee that consent will be granted.

It's always best to check with your local planning authority before you start building. Reputable garden room providers should be able to advise on the planning rules in your particular case too.

If you want additional space that's attached to your property, then planning a conservatory might be a suitable alternative.