A conservatory can provide additional living space, increase natural light, and create a useful connection between the home and garden. In England, many conservatories can be built without a planning application under permitted development rights, provided the relevant conditions are satisfied. The rules for permitted development for conservatories are relatively straightforward, but the size, height, and position of the proposed extension must comply with specific limits. Other restrictions may also apply depending on the property’s type, planning history, and location.
Can a Conservatory Be Permitted Development?
A conservatory can normally be constructed under permitted development rights when it forms a single-storey extension to a house and meets the requirements of Class A. The main restrictions relate to the conservatory’s depth, height, position, and the amount of the property’s curtilage already covered by extensions or other buildings. If the proposed conservatory exceeds any of the relevant limits, planning permission may be required.
Key Permitted Development Rules for Conservatories
Maximum Depth
A standard rear conservatory can extend up to 4 metres beyond the rear wall of a detached house or 3 metres for other houses, including semi-detached and terraced properties. Larger rear extensions may be permitted up to 8 metres for detached houses or 6 metres for other houses, but these are subject to additional requirements, including the neighbour consultation scheme.
Maximum Height
The highest part of a single-storey conservatory must not exceed 4 metres above ground level where it falls under the relevant permitted development rules. Where the conservatory is within 2 metres of a boundary, the eaves must not exceed 3 metres. This restriction should be considered carefully when designing a conservatory close to a neighbouring property.
Position
A conservatory cannot project forward of the principal elevation of the original house or a side elevation that fronts a highway. Its position must therefore be considered in relation to the original building and surrounding boundaries.
Where Can a Conservatory Be Built?
Permitted development rights can allow a conservatory to be built to the rear of a house, provided the relevant Class A conditions are met. The proposed extension must remain within the applicable limits for depth, height, position and site coverage.
The location of the property should also be considered alongside its existing layout, previous extensions and planning history. Where permitted development rights have been restricted or removed, planning permission may be necessary even where the proposed conservatory would otherwise meet the standard limits.
Other Conditions for Conservatories
The permitted development rules for conservatories apply to houses, but they do not generally apply to flats and maisonettes in the same way. The total area of ground covered by buildings within the property’s curtilage, excluding the original house, must not exceed 50% of the total curtilage. Existing extensions, garages and outbuildings can therefore affect whether there is sufficient permitted development capacity for a new conservatory.
The design must also comply with other applicable conditions relating to the extension’s position, roof and windows. Certain locations may have additional restrictions that need to be checked before work begins.
Can a Two-Storey Conservatory Be Permitted Development?
A typical conservatory is single-storey, but a two-storey glazed extension would be subject to the rules for extensions of more than one storey. A two-storey rear extension must not extend more than 3 metres beyond the rear wall of the original house and must be at least 7 metres from the boundary opposite the rear wall. Additional restrictions relating to the roof and windows also apply. Where the proposed design does not satisfy these requirements, a planning application may be required.
Larger Conservatories and Prior Approval
Larger single-storey rear conservatories may benefit from the extended permitted development limits available for larger rear extensions. These provisions allow a rear extension to project up to 8 metres from a detached house or 6 metres from other houses, subject to the relevant conditions and the neighbour consultation scheme.
The larger extension provisions do not apply in every situation. Additional restrictions can apply depending on the property’s location, designation and planning history. The proposed conservatory should therefore be assessed carefully before work begins.
Conservatories on Designated Land
Additional restrictions can apply to properties in conservation areas, National Parks, Areas of Outstanding Natural Beauty and other designated locations. An Article 4 Direction may also remove or restrict permitted development rights in particular areas. Planning conditions attached to an earlier planning permission can place further restrictions on development. A conservatory that would normally qualify for permitted development may therefore require planning permission where the property’s permitted development rights have been restricted.
Do Conservatories Need Building Regulations Approval?
Planning permission and building regulations are separate requirements. A conservatory may be exempt from Building Regulations approval where it meets the relevant conditions, including being built at ground level, having a floor area of no more than 30 square metres and retaining the existing external door between the house and conservatory.
The glazing, electrical installations and other elements of the conservatory must still meet any applicable Building Regulations requirements. Where the exemption conditions are not satisfied, building regulations approval may be required. The permitted development limits and building regulations requirements should therefore be considered separately when planning a conservatory.
Common Conservatory Planning Mistakes to Avoid
Conservatories can be relatively simple additions, but overlooking a permitted development condition can mean that planning permission is required. Common mistakes include:
- Exceeding the permitted depth of the extension.
- Exceeding the maximum height.
- Ignoring the 2-metre boundary and eaves restriction.
- Failing to account for previous extensions.
- Exceeding the 50% curtilage coverage limit.
- Assuming larger rear extension rights apply automatically.
- Failing to check whether an Article 4 Direction applies.
- Assuming permitted development rights apply to flats or maisonettes.
- Ignoring planning conditions attached to the original property.
- Starting construction before confirming that the proposed design is lawful.
Checking the planning position before work begins can help avoid unnecessary delays, enforcement issues or the need to alter completed work.
Should You Apply for a Lawful Development Certificate?
Where a conservatory complies with permitted development requirements, a Lawful Development Certificate can provide formal confirmation that the proposed work is lawful. A certificate is not the same as planning permission. Instead, it confirms that the development falls within permitted development rights and therefore does not require a planning application. Although an application for a Lawful Development Certificate is not always required, it can provide useful evidence of the property’s planning position, particularly when the property is later sold or remortgaged.
How Studio Charrette Can Support Your Conservatory Project
Studio Charrette can help homeowners assess whether their proposed conservatory is likely to fall within permitted development rights and identify where planning permission may be required. Our planning and architectural support can include reviewing the proposed dimensions, checking the position of the conservatory, assessing the property’s planning constraints and preparing the appropriate planning documentation where required. Where a conservatory falls outside permitted development rights, we can also advise on the most suitable planning route for the proposed development.
Making Informed Decisions About Your Conservatory
Permitted development for conservatories can allow homeowners to create additional space without submitting a planning application, provided the relevant conditions are satisfied. The most important requirements include the permitted depth and height, the position of the conservatory, boundary distances, existing extensions and the total amount of development within the property’s curtilage. Larger rear conservatories may benefit from increased permitted development limits but are subject to additional requirements, including the neighbour consultation scheme. Where the project falls outside permitted development rights, a householder planning application may provide the appropriate route.
Before starting work, it is advisable to check the planning position carefully and ensure that the proposed design complies with all relevant requirements. If you need advice on your proposed conservatory, contact Studio Charrette for professional planning and architectural support.
Frequently Asked Questions
Do I need planning permission for a conservatory?
A conservatory can usually be built under permitted development rights if it meets the relevant requirements for house extensions, including the applicable limits on depth, height, position and site coverage.
What is the maximum size of a conservatory without planning permission?
The standard permitted depth is generally 4 metres for a detached house and 3 metres for other houses. Larger rear extensions may be possible under the extended permitted development rules, subject to additional requirements.
How high can a conservatory be without planning permission?
A single-storey conservatory must generally not exceed 4 metres in height. Where it is within 2 metres of a boundary, the eaves must not exceed 3 metres.
Can I build a conservatory close to my neighbour’s boundary?
A conservatory can potentially be built close to a boundary, but where it is within 2 metres of the boundary, the eaves height must not exceed 3 metres.
Can I build a large conservatory under permitted development?
A larger single-storey rear conservatory may qualify under the extended permitted development rules, but the relevant conditions and neighbour consultation requirements must be satisfied.
Do conservatories need building regulations approval?
Some conservatories can be exempt from Building Regulations approval if they meet the applicable exemption requirements. Planning permission and building regulations are separate requirements and should both be considered before construction.
