When Do I Need Planning Permission for an Outbuilding?

Understanding Outbuildings and Permitted Development

In the UK, many outbuildings fall under Permitted Development Rights, meaning you might not need to apply for planning permission if your project meets specific criteria. These rights allow certain small-scale construction and improvements to be completed without the need for formal permission. However, there are limitations and rules that you must comply with, so it’s crucial to understand the details.

Outbuildings that fall under permitted development could include:

• Home Offices
• Garden Rooms
• Workshops or Studios
• Garages
• Storage Sheds

When Planning Permission May Not Be Required

You may not need planning permission if your outbuilding meets the following criteria:

1. Use of the Building:

   • The outbuilding must be used for purposes “incidental” to the enjoyment of your home, such as a gym, storage shed, or home office. This excludes using it as a separate residential accommodation or for business purposes unless it’s a home-based office.

2. Location and Coverage:

   • The outbuilding must not cover more than 50% of the total area of land around the original house. The “original house” refers to the size of the property as it was on 1st July 1948 or when it was first built, whichever is later.

3. Height Restrictions:

   • The maximum height for an outbuilding with a dual-pitched roof (i.e., a sloped roof with two sides) is 4 metres.
   • For other roof types, the maximum height is 3 metres.
   • If the outbuilding is within 2 metres of your property boundary, the maximum height allowed is only 2.5 metres.

4. Proximity to Boundaries:

   • If the outbuilding is placed within 2 metres of any boundary, it must not exceed 2.5 metres in height.

5. Not in Front of the House:

   • The outbuilding must be built behind the principal elevation of your house—so you can’t put it in your front garden without planning permission.

When Planning Permission Will Be Required

Even if your project falls under Permitted Development, there are times when you will still need planning permission:

1. Listed Buildings:

   • If your house is a listed building, planning permission is always required for any outbuilding, as listed properties are under stricter control to maintain their heritage value.

2. Conservation Areas:

   • If your home is located in a conservation area, National Park, Area of Outstanding Natural Beauty (AONB), or World Heritage Site, stricter rules may apply. You may require planning permission for certain designs, sizes, or types of outbuildings to ensure the appearance of the area is not compromised.

3. Building Use Restrictions:

   • If you want to use the outbuilding as a self-contained living accommodation—such as a granny annexe—you will definitely need planning permission. In this case, the outbuilding is considered an extension of your dwelling.

4. Flats and Converted Properties:

   • Permitted Development Rights do not apply to flats or properties that have been converted into multiple units. In these instances, planning permission is required for any outbuilding project.

Building Regulations for Outbuildings

While you might not always need planning permission, you could still need Building Regulations approval, depending on the size and intended use of your outbuilding.

• Small Garden Sheds or Summerhouses typically don’t require building regulations approval.
• Outbuildings that include sleeping accommodation must comply with Building Regulations, covering aspects such as fire safety, structural safety, ventilation, and insulation.
• If your outbuilding has electrical installations, this work must comply with Part P of the Building Regulations, and should be carried out by a certified electrician.

Common Questions About Outbuildings and Planning Permission

• Do I need planning permission for a large shed?
  A larger shed could require planning permission if it exceeds the height limits outlined above, or if it takes up more than 50% of the garden space.

• Do I need permission for a garden office?
  Garden offices used for home-working purposes generally don’t require planning permission if they comply with height and positioning rules. However, if the space will host clients or employees, it will be treated as a business use and planning permission may be necessary.

• What about outbuildings with water or plumbing connections?
  Adding water, a toilet, or a bathroom to an outbuilding doesn’t always trigger a planning permission requirement, but it will trigger Building Regulations to ensure the plumbing and drainage are correctly installed.

Tips for Planning an Outbuilding

1. Be Considerate of Neighbours:

   • Even if you don’t need planning permission, it’s always wise to discuss your plans with your neighbours. If the outbuilding is located close to their boundary, make sure they’re informed. This will help to prevent disputes down the line.

2. Check Your Title Deeds:

   • Some properties have covenants in their deeds that restrict the building of outbuildings. Before proceeding, check your property deeds or consult a solicitor if you’re unsure.

3. Think About Long-Term Use:

   • Consider what you’ll use the outbuilding for in the future. Adding plumbing or electrics now might save you time and money if your needs change, but remember these changes will need to comply with building regulations.

When Do I Need Planning Permission For An Outbuilding

Understanding when you need planning permission for an outbuilding can help you avoid delays and ensure your new garden room, shed, or gym can be enjoyed without complications. Whether your outbuilding requires planning permission or falls under Permitted Development, it’s vital to understand the regulations that apply.

Before starting any building work, it’s best to confirm with your local planning authority or work with a professional architectural designer like Surv Essex, who can provide all the necessary drawings and handle planning permission submissions on your behalf. By doing things by the book, you can enjoy your outbuilding with complete peace of mind.