Planning Permission
Granny annexe planning permission, explained
The most common question we're asked is simple: do I need planning permission for a granny annexe? For a qualifying Booths annexe, the answer is usually no — and the reason is a piece of legislation most people have never heard of.
- 25 Year
- Guarantee
- Free
- UK Delivery
- Zero
- Maintenance
The Caravan Sites Act 1968, Section 13(2)
A building that meets the legal definition of a "caravan" — even a large, fully-fitted twin-unit one — can be stationed within the curtilage of a house and used by the family without a separate planning application. Our annexes are designed and manufactured specifically to comply with this definition: twin units that are bolted together as the final act of assembly on your site.
Maximum dimensions
These limits are generous — they comfortably accommodate a one or two-bedroom annexe with a full kitchen and bathroom.
The conditions you must meet
- ✓ The annexe is occupied by a member of your family (a blood relative).
- ✓ It is positioned to the side or rear of the main house, not in front.
- ✓ It does not cover more than 50% of the garden area.
- ✓ It remains moveable — assembled by bolts as the final act of assembly.
- ✓ It is used in connection with the main dwelling, not sold off separately.
When it does not apply
The Caravan Act route has limits. Planning permission may still be required where the property is one of the following:
- ! Listed buildings and their curtilage
- ! Areas of Outstanding Natural Beauty (AONB)
- ! Flats and maisonettes
- ! Properties with new-build covenants restricting outbuildings
We confirm this for your garden
Before installation we assess your specific situation in writing — positioning, garden coverage and any local restrictions — so you have certainty, not assumptions. This guidance is general; we are annexe specialists, not solicitors, and complex cases may warrant legal advice.
Ask us about your gardenPlanning permission questions
Can I attach my annexe to my house?
No — annexes cannot attach to existing properties, but can be positioned within about 2 inches of the home or garage.
How do I buy a garden annexe?
A £1,000 deposit reserves your installation date; you pay nothing more until the groundworks team arrives. Designers email floor plans and conduct a site visit to finalise the design, which must be confirmed 15 working days before installation.
What height is my garden annexe?
All annexes are 2,500mm tall, which falls within permitted development for garden structures.
What is included in the annexe price?
Groundworks (up to 20m), electrical connections, air-conditioning heating/ cooling, flooring, blinds and exterior lights — plus the 25-year guarantee.
Is my garden annexe insulated?
Yes — 90mm Ecotherm flooring and 90mm Actis wall/ceiling insulation. As an annexe faces weather on six sides, robust insulation is essential.
Listed building or AONB — can I still have an annexe?
Contact your council and emphasise the low carbon output — some planners have approved installations. Material samples are available on request.
Will I need planning permission for my annexe?
Annexes for a family member comply with the Caravan Act and qualify as permitted development, avoiding planning permission. See the Planning Permission page for the full conditions.
What are your most popular annexe sizes?
The Squire (16'x17'), Rockingham (20'x17') and Lincoln L-shape (24'x8' / 12'x8'). For smaller gardens, 20'x8' or 24'x8' with kitchen and bathroom are favoured.
If I move home, can I take my garden annexe with me?
Yes — portability is a core design principle. Even large annexes with kitchens and bathrooms remain portable, provided Booths installed those fixtures.
Can I attach a studio or annexe to my house?
No — studios, offices and annexes cannot be attached to existing properties, though they can be positioned within about 2 inches of one.
Do I need a concrete base?
No. Studios sit on an adjustable chassis on concrete feet resting on soil, grass or gravel — significant cost savings, installable on sloped ground, and a lower-carbon alternative to a concrete base.
Do I need planning permission for decking?
Yes if the decking is 300mm or more above ground; no if below 300mm.
I live in a Grade 2 listed building and/or an AONB — is this an issue?
It can be a sticking point, but customers emphasising the low carbon output have gained approval. Contact your council first; describe the three materials (A-grade UPVC windows, plasti-coated galvanised steel walls, corrugated bitumen roof). We provide samples and elevation drawings to help.
Do I need garden office planning permission?
Probably not — the 2.5m height qualifies as permitted development. If you handle planning yourself we supply drawings free of charge, and a planning consultant is available. Caravan-Act annexes need no planning permission.
I have a severely sloped garden — can you still install a garden studio?
Yes. Installation is possible on a severe slope without a concrete base; a studio skirt is available if desired, or you can plant beneath. Foxes living underneath is extremely rare — zero instances in company history.
What height is the garden studio?
All studios are 2,500mm high, which typically requires no planning permission as it falls within permitted development, even with a flyover roof. An extended-height option adds roughly 300mm of interior height.
Thinking about a granny annexe?
Talk to a specialist about planning, sizes and the Caravan Act for your home.