Planning Guidance
Capsule Homes are often classed as either outbuildings or mobile homes, depending on their design and use.
If you do need to apply for Planning Permission, we recommend seeking professional advice — and it’s always wise to check with your local Planning Authority.
Garden Office Planning Permission Checklist
In most cases, garden offices and similar outbuildings are classed as Permitted Development under national planning rules, meaning Planning Permission may not be required.
Your Capsule Home may fall under Permitted Development if:
·• It’s single-storey
·• It’s no more than 2.5m high if within 2m of a boundary
·• It’s no more than 3m high if further away from boundaries
The building must also be used for purposes incidental to the enjoyment of the dwellinghouse — such as a home office, studio, or gym.
If your plans meet these criteria, Planning Permission is likely not required, but it’s important to confirm with your local Planning Authority.
Granny Annex Planning Permission
This applies if you plan to install a mobile home in your garden for a family member’s exclusive use.
You may not need Planning Permission if you can answer “Yes” to both of the following:
1. Does the annex meet the legal definition of a mobile home under the Caravan Sites Act 1968? (All Capsule Homes do.)
2. Will it remain ancillary to the main house — i.e. not sold, let, or occupied independently by non-family members? If so, full Planning Permission is usually not required.
However, we strongly recommend applying for a Lawful Development Certificate (LDC) to confirm your legal position. We offer this as part of our Granny Annex package.
Transportable / Mobile Home Planning Permission
If you plan to site your Capsule Home outside the garden of a main dwelling, you will almost always require Planning Permission.
One exception: if you're replacing a mobile home that has been continuously and lawfully sited for over 10 years, you may be able to apply for a Lawful Development Certificate instead.
You’ll need clear supporting evidence — such as council tax records, utility bills, or a sworn affidavit — to prove its lawful use. The replacement unit must still meet the Caravan Act definition of a mobile home.
Talk to our in-house planning adviser today and get expert guidance tailored to your project.