You can't just build a house on your land, no matter how good the story!
The news that a family is being asked to remove their house on their land where they look after an Alpaca retreat is not surprising, in this country there are planning laws and you are never far away from people who know the rules and do not want to see them flouted by their neighbours. The story is outlined and published in Homebuilding and Renovation.
The first thing that these people should do is to apply for planning permission for their home, in the absence of this the Local Planning Authority have no recourse but to pursue enforcement. With a live planning application the planning authority will usually give the applicants the opportunity to state their case, which will at least give them more time. If the case is not proven, then they might be refused, but If they can prove that their home is temporary and the animals need constant care, then at the least they might be given a temporary approval for a limited time in order to maintain their home and look after the Animals on the land. If they can prove that their cause is worthy, then in due course it may be possible to gain permanent planning permission for a dwelling with an Agricultural Tie.
PAPA SAYS - If they are refused permission, then they can appeal and if subsequently refused then this could stall the inevitable by up to a year. If they don't have sufficient funds to do this although relatively inexpensive, then a bit of crowd funding from lovers of Alpacas would most likely comfortably cover that cost.