Adding an outbuilding to your garden can be an excellent way to create additional space without extending the main house. Whether you are considering a garden office, home gym, workshop, garage, storage building, or another type of garden room, you may be wondering whether you need planning permission.
In some circumstances, an outbuilding can be constructed under permitted development rights, meaning that a full planning application may not be necessary.
However, permitted development is subject to specific conditions and limitations. Getting one of these requirements wrong can mean that a structure you believed was permitted development actually requires planning permission.
This is particularly important where an outbuilding is close to a boundary, takes up a significant part of the garden, exceeds the permitted height, or is intended for a purpose that falls outside the relevant permitted development rules.
At Charrette Law, we advise homeowners, landlords, developers, and property owners on permitted development rights and planning law. If you’re considering building an outbuilding and are unsure whether planning permission is required, obtaining advice before construction begins can help you avoid unnecessary expense and potential enforcement action.
In this guide, we’ll explain how permitted development rights apply to outbuildings, the key restrictions you need to understand, and when you should seek professional planning advice.
What Is an Outbuilding?
An outbuilding is generally a detached structure within the grounds of a house.
Common examples include:
- Garden offices
- Home gyms
- Workshops
- Garages
- Garden rooms
- Storage buildings
- Studios
- Hobby rooms
- Shelters and other garden structures
The fact that a structure is located in your garden does not automatically mean that it falls within permitted development.
Its size, height, location, intended use, and relationship with the main house can all be relevant when determining whether permitted development rights apply.
This is why it is important to assess the proposed structure as a whole rather than assuming that a small building will automatically be exempt from planning permission.
Can You Build an Outbuilding Without Planning Permission?
In many cases, an outbuilding can benefit from permitted development rights.
Permitted development rights allow certain types of development to take place without submitting a traditional planning application, provided the development meets the relevant statutory requirements.
For outbuildings associated with a house, these rights can cover certain buildings within the property’s curtilage.
However, there are important limitations.
For example, permitted development rules can restrict:
- The height of the building.
- Where can the building be positioned?
- The amount of land that can be covered.
- The use of the building.
- Whether the property is a listed building.
- Whether the property is located in a designated area.
- Whether permitted development rights have been removed or restricted.
The specific circumstances of your property therefore matter.
At Charrette Law, we can assess your proposal and advise whether your proposed outbuilding is likely to fall within permitted development rights or whether a planning application may be necessary.
What Are the Permitted Development Rules for Outbuildings?
There are several important rules that need to be considered before constructing an outbuilding under permitted development rights.
The Outbuilding Must Be Within the Property’s Curtilage
Permitted development rights for outbuildings generally relate to buildings within the curtilage of a house.
This means that the location of the proposed structure in relation to the main dwelling and its surrounding land is important.
Simply owning land next to a house does not necessarily mean that the land benefits from the same permitted development rights.
If you’re unsure whether the proposed building is within the relevant curtilage, professional advice should be obtained before work begins.
What Can You Use an Outbuilding For?
The intended use of the outbuilding is also important.
Permitted development rights generally allow certain incidental uses associated with the enjoyment of the dwellinghouse.
For example, a garden building used as:
- A home office
- A gym
- A hobby room
- A games room
- Storage
May potentially fall within permitted development, subject to the applicable restrictions.
However, using an outbuilding as a separate residential dwelling raises different planning considerations.
An outbuilding designed to provide independent accommodation, particularly where it has its own living, sleeping, cooking, and bathroom facilities, may not benefit from the same permitted development rights.
This is one area where homeowners can easily make an expensive mistake.
Before converting a proposed garden building into independent accommodation, it is advisable to establish whether planning permission is required.
Outbuilding Height Restrictions
Height is another important consideration when planning an outbuilding.
Permitted development rules contain specific restrictions concerning the height of detached buildings within the curtilage of a house.
The permitted height can depend on factors such as the type of roof and the building’s proximity to the property boundary.
Where the proposed structure is close to a boundary, additional restrictions can apply.
This means that simply designing an outbuilding to fit comfortably within your garden is not enough. Its measurements need to be checked against the applicable permitted development requirements.
At Charrette Law, we can advise on the planning implications of your proposed dimensions before you commit to construction.
How Much of Your Garden Can an Outbuilding Cover?
Another important consideration is the amount of land that can be occupied by extensions and other buildings within the curtilage.
Permitted development rights are not intended to allow homeowners to cover their entire garden with buildings.
The relevant restrictions take into account the proportion of the property’s curtilage that can be covered by buildings.
This means you should consider the existing extensions, conservatories, garages, sheds, and other structures on the property when assessing whether your proposed outbuilding complies.
A new garden room may appear small in isolation but still create a problem when considered alongside existing development.
Thinking About Building an Outbuilding?
Before ordering materials or starting construction, it is worth checking whether your proposed structure actually benefits from permitted development rights.
At Charrette Law, we can help you understand the planning rules that apply to your property, identify potential issues, and advise whether you should proceed under permitted development or consider making a planning application.
Contact Charrette Law today to discuss your proposed outbuilding with our planning team.
When Does an Outbuilding Need Planning Permission?
An outbuilding may require planning permission where it does not comply with the relevant permitted development conditions and limitations.
This could happen because:
- The proposed building is too large.
- It exceeds the relevant height restrictions.
- It is positioned incorrectly.
- The proposed use is not permitted.
- The property is subject to restrictions on permitted development.
- The building is associated with a different type of property.
- The site is located within a designated area where additional controls apply.
Planning permission may also be necessary where the proposed development goes beyond what permitted development rights allow.
Rather than relying on assumptions, it is better to establish the planning position before work begins.
Do Permitted Development Rights Apply to Every Property?
No.
Certain properties and locations can be subject to additional planning controls.
For example, additional considerations may apply to:
- Listed buildings
- Conservation areas
- National Parks
- Areas of Outstanding Natural Beauty
- The Broads
- World Heritage Sites
Permitted development rights may also have been removed or restricted by the Local Planning Authority.
For example, an Article 4 Direction can remove certain permitted development rights within a particular area.
This is why advice based purely on the size of the proposed outbuilding may be incomplete.
If you are unsure whether your property benefits from permitted development rights, our article on Permitted Development Rights provides further information about how these rights work and the restrictions that can apply.
What If You Build an Outbuilding Without the Required Permission?
One of the biggest risks is starting construction before confirming the planning position.
If an outbuilding does not benefit from permitted development rights and planning permission was required, the Local Planning Authority could take enforcement action.
Depending on the circumstances, you may be asked to:
- Apply retrospectively for planning permission.
- Alter the building.
- Stop using the building.
- Remove the structure.
In serious cases, enforcement action can result in high costs and disruption.
Seeking professional advice before construction begins is therefore usually much less expensive than trying to resolve a planning problem afterwards.
At Charrette Law, we advise property owners on planning enforcement and can help assess the available options where an outbuilding has already been constructed.
Outbuildings and Permitted Development: Why Professional Advice Matters
Permitted development can make smaller development projects considerably easier, but it should not be treated as a blanket exemption from planning control.
The rules contain detailed conditions and limitations, and the exact circumstances of your property can make a significant difference.
A small change in dimensions, positioning, or intended use can affect whether permitted development rights apply.
This is particularly important if you are investing significant money in a garden office, gym, studio, workshop, or other permanent structure.
At Charrette Law, we help clients understand the planning position before they commit to construction. Where permitted development is not available, we can also advise on the planning options available to you.
How Outbuilding Permitted Development Fits Into Your Wider Planning Strategy
An outbuilding is only one example of how permitted development rights can be used to make changes to a property.
Depending on your circumstances, you may also be considering:
- A house extension
- A loft conversion
- A garage conversion
- Additional storeys
- A change of use
- Development on Green Belt land
If your proposed project involves Green Belt land, our guide on Permitted Development Rights and Green Belt Land explains some of the additional planning considerations that may apply.
If your project does not qualify for permitted development and you need to make a planning application, our Planning Drawings guide explains why accurate drawings are important and how they help the Local Planning Authority understand the proposed development.
And if your planning application is refused, you may want to read our guide on Planning Appeals, which explains the options available for challenging certain planning decisions.
Why Choose Charrette Law?
Planning rules surrounding outbuildings can be complicated, particularly where a property has already been extended or is subject to additional planning restrictions.
At Charrette Law, we provide practical planning and property law advice to homeowners, developers, landlords, and investors.
We can assist with:
- Permitted development advice.
- Outbuilding proposals.
- Planning applications.
- Planning enforcement matters.
- Planning appeals.
- Planning objections.
- Green Belt development.
- Planning conditions.
- Wider property and planning issues.
Our aim is to help you understand your options before committing to a development, reducing the risk of unexpected planning problems later.
Speak to Charrette Law About Your Outbuilding
If you’re planning to build a garden office, gym, workshop, garage, studio, or another outbuilding, don’t assume that planning permission isn’t required simply because the structure is in your garden.
The size, height, location, use, and planning history of your property can all affect whether permitted development rights apply.
At Charrette Law, we can review your proposed development and help you understand the planning position before you begin construction.
Contact Charrette Law today to discuss your proposed outbuilding and receive practical planning advice tailored to your property.
Frequently Asked Questions
Can I build an outbuilding without planning permission?
Potentially. Certain outbuildings can be built under permitted development rights if they meet all the relevant conditions and limitations. The specific circumstances of the property and proposed development need to be considered.
What size can an outbuilding be without planning permission?
There isn’t one universal size that applies to every outbuilding. The permitted development rules contain restrictions relating to factors including height, location, and the proportion of the curtilage covered by buildings.
Can I use my outbuilding as a home office?
A home office may potentially fall within permitted development where it is used for a purpose incidental to the enjoyment of the dwellinghouse. However, the specific design and use should be considered before construction.
Can I live in an outbuilding?
Using an outbuilding as a separate dwelling can raise different planning issues. Independent residential accommodation may not benefit from the permitted development rights that apply to ordinary incidental garden buildings.
Does an outbuilding need planning permission if it is close to the boundary?
Not necessarily, but additional restrictions can apply where an outbuilding is close to a boundary, particularly concerning its height. The proposed dimensions and location should be assessed against the applicable permitted development rules.
Do permitted development rights apply to listed buildings?
Additional restrictions apply to listed buildings, and permitted development rights should not be assumed to apply in the same way as they would to an ordinary dwelling.
Can I build an outbuilding in a conservation area?
Possibly. Additional restrictions can apply in conservation areas and other designated areas. The location and nature of the proposed development should be assessed before construction.
What happens if I build an outbuilding without planning permission?
If planning permission was required and the development does not benefit from permitted development rights, the Local Planning Authority may take enforcement action. Depending on the circumstances, you may need to seek retrospective permission, alter the building, or remove it.
Can Charrette Law advise me before I build an outbuilding?
Yes. Charrette Law can advise on whether your proposed outbuilding is likely to benefit from permitted development rights, whether additional planning controls apply, and what options may be available if planning permission is required.
