A mobile home on a garden plot: a walkthrough

Mobile home garden planning questions nearly always come down to one issue: whether the caravan is being used as part of the existing house or as a separate home. A caravan parked in a garden and used for storage, as a hobby room or as an occasional spare bedroom by the household is usually incidental use of the curtilage and needs no permission. A caravan occupied as an independent household, with its own kitchen and bathroom and its own front door, is a separate dwelling, and that is a material change of use.

This walkthrough is illustrative. It follows a composite householder case built from the pattern these disputes take, not a real decision, and no figures are quoted from one.

The plot, the caravan and the intended occupation

A 1950s semi with a long rear garden. The family had an adult son who needed somewhere to live, and the house had run out of bedrooms. They bought a secondhand static caravan, had it craned over the side boundary, levelled it on blocks with the wheels removed, and built a timber deck around three sides.

They then connected it to the mains electricity supply from the house consumer unit, ran a water supply, and connected the waste to the foul drain. The caravan had a small kitchen with a cooker and a shower room already fitted.

The son moved in, used the side gate as his own entrance, and paid his parents a monthly contribution. Eighteen months later the neighbour on the other side complained about the deck, the overlooking and the extra car.

When a caravan becomes a material change of use

Two separate legal regimes apply and they are easy to confuse.

Site licensing sits under the caravan site legislation of 1960 and 1968. The use of land within the curtilage of a dwellinghouse for stationing a caravan, where that use is incidental to the enjoyment of the dwellinghouse, is exempt from the site licence requirement. That exemption is about licensing, not about planning, and relying on it as a planning answer is the most common mistake in this area.

Planning sits under section 55 of the Town and Country Planning Act 1990. The question is whether there has been a material change in the use of the land, and the usual analysis asks whether a new, separate planning unit has come into existence.

There is also a question about whether the caravan has become a building. The long established test looks at size, degree of permanence and degree of physical attachment to the ground. A caravan on blocks with its wheels removed, surrounded by a fixed deck and hard connected to mains services, is a long way along that spectrum, and the further along it goes the harder it is to argue that nothing more than the stationing of a caravan has occurred.

The incidental and ancillary arguments tested

Two different arguments were available and the family ran the weaker one.

The incidental argument is that the caravan serves a purpose incidental to the enjoyment of the house, such as storage, a workshop, a playroom or a home office. It fails as soon as someone lives in it, because living accommodation is not incidental to a dwelling, it is a use of the same kind.

The ancillary argument is stronger and it is the one that works for annexes. A caravan occupied by a member of the same household, functionally dependent on the main house, sharing facilities and forming part of a single planning unit, can be ancillary accommodation rather than a separate dwelling. Grandparents, an adult child who eats with the family and uses the main bathroom, a carer.

The factors officers weigh are familiar and consistent:

• whether there is a separate kitchen capable of independent cooking
• whether there is a separate bathroom
• whether there is a separate entrance and whether the occupier can come and go without using the house
• whether the occupier is a member of the household or an independent household
• whether rent is paid and whether the unit could be let or sold separately
• whether the unit has its own council tax band
• whether there is physical and visual separation, such as fencing or separate parking

On those factors the composite case failed. Separate cooking, separate shower room, separate entrance, a monthly payment and an occupier living independently. That is a separate dwelling in substance regardless of the family relationship.

The enforcement investigation and its findings

The council began with a planning contravention notice under section 171C of the 1990 Act, which requires the recipient to provide information about the use of the land. It is not an enforcement notice and it is not optional, and the answers given are evidence.

The family answered it honestly, which was the right decision and also confirmed the council's case. The officer then visited, photographed the deck and the connections, and checked the council tax position.

The findings were that a material change of use had occurred from a single dwellinghouse to two dwellings, that the deck was development in its own right and exceeded what the householder permitted development rights allow because of its height above ground at the far end, and that the caravan's degree of permanence meant it fell to be treated as a building rather than as a stationed caravan.

An enforcement notice followed, requiring the use as a separate dwelling to cease, the connections to be removed and the deck to be taken down, with a compliance period of six months.

The temporary permission sought

The family appealed the notice and, on advice, also made a retrospective application. That dual track is usually the right approach, because the appeal preserves the position while the application offers the council a way to say yes.

The application was not for what existed. It was for an ancillary annexe, which meant changing the proposal: removal of the cooker and the independent cooking facility, retention of a sink and a small fridge, retention of the shower room, removal of the separate side gate access so that the annexe is reached across the garden from the house, and reduction of the deck to a single low platform at the entrance.

The supporting material was short and specific. Existing and proposed plans, photographs, a schedule of the works to be carried out and a Planning Statement setting out the ancillary case against the factors above, the family circumstances and the local plan policy on annexe accommodation.

Most authorities have a policy on residential annexes, and reading it before drafting the application is the single highest value hour in the exercise.

Conditions on occupancy and duration

Temporary permission was granted for three years, with conditions.

1. The accommodation shall be occupied only by a member of the family occupying the main dwelling, or a person dependent on them, and shall not be occupied as a separate dwelling.
2. The caravan and the deck shall be removed and the land restored within three months of the accommodation ceasing to be so occupied.
3. No independent cooking facilities shall be installed.
4. No separate vehicular or pedestrian access shall be formed to the highway.
5. The caravan shall not be sold, let or otherwise disposed of separately from the main dwelling.

Condition one is the one that gives the permission its value and its limits. An occupancy condition tied to the household means the annexe cannot become an income stream, which is exactly the point from the council's perspective and the reason some families decline the permission and remove the caravan instead.

Condition two matters on sale. A buyer's solicitor will see the condition, and the caravan becomes a liability rather than an asset in the valuation.

How the position was regularised

The works were carried out, the council confirmed compliance, and the enforcement appeal was withdrawn. The total cost was the application fee, the drawings, the advice, the removal of the cooker and most of the deck, and a year of unpleasantness with a neighbour.

What would have avoided it: establishing at the outset whether the intended occupation was ancillary or independent, designing the accommodation to match that answer, applying before the caravan arrived, and telling the neighbour. Where the plan is independent accommodation from the start, the honest route is an application for a new dwelling, assessed on its own merits, which on a long garden plot in a suburban street is sometimes achievable and sometimes not.

Builders' caravans are a separate matter worth knowing about. Permitted development rights allow temporary buildings and structures needed in connection with building operations for the duration of those operations, which is how a caravan can lawfully sit on a self build plot during construction. That right ends when the works end. On the practical side of building work next to a neighbour, a party wall notice can delay a rear extension programme in much the same way an enforcement case does.

If you are assembling an application pack, you can see which documents are usually involved across the 66 report types.

This is general guidance, not legal advice, and the walkthrough is illustrative rather than a report of a real decision. A lawful development certificate is the only formal way to confirm that a use is lawful. Check the position with your local planning authority or a qualified professional before relying on it.

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