Lawful development certificate

It’s all in the detail

To ensure your garden room or mobile home is lawful you can apply for a lawful development certificate from the Local Planning Authority. There are two types of these: certificates for proposed developments and certificates for existing developments.

Proposed use or development

Certificates for a proposed use or development ensure that a proposed residential extension (for instance, an incidental garden room) falls under permitted development.

If you rely on the Caravan Act to site a mobile home within your garden, a Certificate of Lawfulness can be invaluable. Despite the caravan laws being very clear, some Local Planning Authorities (LPAs) may raise objections to your building, especially if complaints have been received. A good way to avoid issues further down the road is to ask a planning consultant to check that your structure does indeed comply with the Act. If it does, it won’t require planning permission, so your consultant can apply for a Certificate of Lawfulness on your behalf to ensure the LPA agree.

A Certificate of Lawfulness can also be used to protect yourself should any complaints be raised. Although they aren’t a legal requirement, some situations demand a certificate for any garden structures. For example, should you want to sell your home, your solicitor will almost certainly want to see a Certificate of Lawfulness for your garden room or mobile home to guarantee it is lawful.

Existing use or development

The second type of certificate is for an existing use or development.

This is commonly used to demonstrate that a use or development has been in existence for a certain length of time – and therefore becomes lawful by default and immune from enforcement action. This time span is generally 4 years for applications relating to residential matters, or 10 years for commercial or agricultural applications and breaches of conditions. We find this is an excellent strategy for making the case that an existing garden room meets the permitted development criteria.


Annexe| Garage| Planning Permission
Annexe| Caravan Act| Certificate of Lawfulness| Mobile Homes| Planning Permission
Certificate of Lawfulness| Mobile Homes
Annexe| Certificate of Lawfulness


Annexes are now a popular addition to many family homes to provide additional accommodation.

Mobile Home

NAPC provide a service to help you establish whether your mobile home meets the definition of a caravan and can apply for a Certificate of Lawfulness

Garden Room

Looking to install a garden room at your property? Unsure about planning permission or building regulations for garden rooms?

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