Taken from - safeguard uk caravan laws
Can you park a caravan on the road?
Yes, it’s possible to park a caravan on the road, although the law isn’t always that clear on when it is and isn’t acceptable – it’s something of a grey area!
The main considerations from a legal point of view is that it doesn’t cause an obstruction, or it isn’t parked dangerously. If you do either of these things, your caravan will be judged to be parked illegally, and it will need to be housed elsewhere. If you do decide to park your caravan on the road, you’ll need to ensure that you do so as considerately as possible for the other residents in your street.
You must make sure you do the following:
Ensure that the caravan is lit at night
Park it with the nearside facing the pavement so the rear lights are at the rear and visible for approaching traffic
Is planning permission required to store caravans?
You don’t need planning permission to store a caravan in your garden or on your drive. However, you may need to secure planning permission if you keep it on your property anywhere other than these places.
In some instances, caravans parked on farmland may require different planning permission, as will caravans parked on a large piece of land that includes a protected nature area, even if you own the land.
If you are using a touring caravan as a completely self-sufficient home, and not as an extension of your current home, then you will need planning permission.
You'd think they'd be considerate enough to park it outside their own house