By the sounds of it you are going to be placing an outlet on the wall of your house, and trailing the cable to the caravan. I see no problems with this.
There is no requirement to lock off the outlet or to have it switched, it is upto you if you want to add these features.
You need to consider your earthing arrangements as a PME supply is not permitted to be used with a caravan hookup point. You may need to convert the earthing system for this circuit to a TT system.
To comply to the regs regarding caravan hookups you would need to provide an MCB and an RCD (or an RCBO) for just purely this one outlet.
The outlet should be mounted between 0.5 and 1.5 meter.
I am *pretty* sure the maximum length of the hookup lead is 20m, and so the hookup point should be within 20m of the caravan. TBH, in a situation at home I would want it ALOT closer! Especially if you intend on leaving it connected for some time.
To comply to the regs with regards caravan hookups, you should be using a 16amp cee-form type outlet and not a 13amp socket.
In saying all this, I am sure most caravan owners have a 13amp plug to 16amp appliance coupler in their box of bits, and use this to power the caravan from a convenient socket at home. All the above regulatory precautions being thrown to the wind!
As a matter of point, if you where to fit a standard MK Masterseal type 13amp socket, it could be positioned at any reasonable height, could form part of another circuit and be part of a PME system. The only requirement would be the RCD. I am not saying that this is suitable or safe to be used with a caravan