Maybe, and that would be reasonable in terms of common sense. However, in terms of what is actually written in 'the law', that would seemingly only be the case if the caravan qualified as a 'dwelling' (which is not usefully defined)In my humble opinion any electrical supply that is shared with a dwelling comes under Part P
It may be "obvious" to you, but I'm not sure about even that. The notes to Part P which seek to explain its scope certainly don't say that., the obvious example is the flat above the pub or shop makes the whole pub or shop come under Part P as well.
It is true that that 'scope' includes:
...and you may feel that (c) [and maybe even {a) ] apply to a static caravan.The requirements of this Part apply only to electrical installations that are intended to operate at low or extra-low voltage and are—
(a) in or attached to a dwelling;
(b) in the common parts of a building serving one or more dwellings, but excluding power supplies to lifts;
(c) in a building that receives its electricity from a source located within or shared with a dwelling; or
However, we still seem to come back to the point I mentioned recently, that the scope of The Building Regulations as a whole (including 'Part P', and everything else) seems to be restricted to "buildings" - which, although noty usefully defined as such, explicitly excludes "another kind of structure or erection"
As with so many of these things, it all seems to fsll far short of being as clear as it ought to be
Kind Regards, John