Leisure Use
Caravans, whether built to BS 3632 or EN 1647 are on a wheeled chassis, so are therefore classed as moveable. There is no law preventing one being kept in a garden, but you will still need to observe rules relating to the use of the land.
Where there is no material change of use and the unit is used by the main property / landowners, or for their visiting guests, then that does not constitute a change of use. However, if it is to be sublet or used for a different purpose, then that may require planning permission through the local authority prior to siting. If sited outside of the immediate curtilage, in adjoining land or woodland that will also need permission.
For your own peace of mind, we would recommend you apply to the council for a ‘Certificate of Lawfulness’, as this will give you complete peace of mind and confidence ahead of your purchase. You don’t have to submit detailed plans for this.