Caravan Act, PD & Full Planning Explained

Granny Annexe Planning Permission in
Southampton

Whether it’s a mobile annexe under the Caravan Act or a permanent structure needing full planning permission, Southampton projects of this scale benefit from a Lawful Development Certificate confirming the position in writing, not just an assumption.

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Local to Southampton
Three Routes Explained
Council-Ready Applications

Granny Annexe Planning Permission In Southampton, Explained Properly

The planning position for a Southampton annexe comes down to two questions, is it genuinely mobile within the Caravan Act’s size limits, and is it genuinely ancillary to the house rather than a separate, independent dwelling.

A structure meeting the caravan definition, movable by road, built in no more than two sections, within 20 metres by 6.8 metres by 3.05 metres internal height, can often be sited in a Southampton garden without full planning permission, provided it stays ancillary.

Where a Southampton annexe is permanently fixed, or genuinely self-contained with its own facilities used independently, the caravan and permitted development routes generally don’t apply, and a full application becomes the realistic path. A Southampton annexe needing full planning permission usually needs both, our Building Regulations drawings in Southampton service covers the technical compliance side, and our structural calculations in Southampton service covers the engineering detail.

Right Route Confirmed

Caravan Act, permitted development, or full planning

Caravan Act Route

Movable structures that may need no permission at all

PD Size & Siting

Permitted development limits checked properly

Council-Ready

Applications built to be approved

Granny annexe planning permission

How We Help in Southampton

We start every Southampton annexe project by establishing the real starting point, a mobile structure within Caravan Act limits, an incidental outbuilding, or genuine independent living space, since that single distinction shapes everything that follows.

Your Southampton application or certificate, whichever applies, is built around what your local council specifically expects to see, not a generic template.

Structural and building regulations work for Southampton annexe projects is handled properly from the outset, informed by real experience with this kind of project.

Southampton Granny Annexe Projects Done Properly

Honesty about what your Southampton annexe actually needs comes before any recommendation, not after we’ve quoted for the more expensive route.

We understand the genuine legal distinction between incidental and self-contained use for Southampton annexe projects, which is exactly what most generic guidance gets wrong.

A Lawful Development Certificate, where your Southampton annexe genuinely qualifies for it, gives you written confirmation rather than a risky assumption. If you need help with a granny annexe, give us a call on 0330 133 5316 or fill in the form below.

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Southampton Granny Annexe Questions Answered

Can I build a granny annexe in Southampton without planning permission?

Not automatically, a mobile structure meeting the Caravan Act’s size and mobility test, or a genuinely incidental outbuilding, can potentially avoid it in Southampton, but a self-contained annexe with its own facilities used independently usually can’t.

Can my Southampton annexe qualify as a mobile home?

Yes, potentially, if your Southampton annexe meets the legal size limits, 20 metres by 6.8 metres by 3.05 metres internal height, and is genuinely capable of being moved by road, it may qualify as a caravan under the 1968 Act.

Does Class E cover a granny annexe in Southampton?

Class E permitted development in Southampton covers incidental structures like a home office or gym, subject to height and coverage limits, but not genuine independent living accommodation with its own bedroom, bathroom, and kitchen.

When does my Southampton annexe need full planning permission?

Once a Southampton structure functions as independent living space, its own facilities, used separately from the household, it’s no longer incidental, and neither permitted development nor the Caravan Act route typically applies.

Should I get written confirmation for a Southampton annexe?

Yes, this is genuinely worth having for Southampton projects, confirming the position in writing protects you if the classification is ever questioned, especially at the point of sale.

Do you coordinate the full annexe process for Southampton properties?

Absolutely, Southampton annexe clients get the planning classification and building regulations detail handled together, not as separate, disconnected pieces of work.