living in static and renting out house - Public forum - Planning Advisory Service (PAS)

hello.                                                                                                                                                                                                                                                           Im wondering if someone can shed some light on this for me.  We recently purchased a property that has an adjoining field, in witch a static caravan is sited, it comes with a certificate of lawful use for ancillary residential use.  due to financial problems we would like to rent out our house and live in said caravan ( it would first need replacing or re-building as its no longer habitable in its current condition.) I recently paid an independent planning adviser for his take on this, and have been told its fine to do so. But the more research i do online the more i find conflicting advise. Any advise would be greatly appreciated at this stage.                                                                                                                                     many thanks .                                                                                                                                                                                                                                                       paul.