Planning req for mobile home?

Hi, Hope this q is in the right place. Basically I live and work around 5 hrs away from 'home'.
When I go back to visit I don't want to invade my parents house so would like to put a mobile home/ small timber cabin around 35ft long in a field we own. Area is beside the sea so these are quite common in the area.(I don't feel ready to build there yet.)
Would like to know if this requires planning permission. Tried the website but can't find any answers. Has anybody done this before?
Thanks
W

I'm afraid you'll need planning, the exemption as regarding caravans
means that it can't stay for longer than 10 days (rural area).

the exempted development details are as below:

CLASS 1

Temporary use of any land for the placing of any tent, campervan or caravan or for the mooring of any boat, barge or other vessel used for the purpose of camping.
1. Not more than one tent, campervan or caravan shall be placed within 100 metres of another tent, campervan or caravan at any time.
2. No tent, campervan, caravan or vessel shall remain on the land for a period greater than 10 days.
3. No tent, campervan, caravan or vessel shall be used for the storage, display, advertisement or sale of goods or for the purposes of any business.
4. No tent, campervan or caravan shall be placed on land within 50 metres of any public road unless the land is enclosed by a wall, bank or hedge, or any combination thereof, having an average height of not less than 1.5 metres.

Click to expand...

Many thanks for the information