R (Hand) -v- Secretary of State for Communities and Local Government  EWHC 314 (Admin), 23 January 2014
Town and County Planning Act 1990 Section 171 B (3) states that enforcement action can be taken against the use of land in general within 10 years from the use commencing. However, use of a building as a dwellinghouse becomes immune from enforcement and, therefore, lawful after 4 years.
On the evidence of this case, the former mobile home in question was fixed at one end by bolts to a concrete wall. A wooden porch had been constructed outside the door and a wooden lean-to extension had been added. It had supplies of heating, water and power connected underground and waste connected to a separate tank. The towing bar had been removed. The Planning Inspector refused the application for a Lawful Use Certificate. An appeal was made to the High Court where Robin Purchas QC, sitting as a Deputy High Court Judge, dismissed the appeal stating:-
The limited extent of the base wall and limited number of fittings and limited attachment of the deck would not prevent removal of the unit and it would be a fairly straightforward and relatively quick operation to separate them from the unit. The porch and rear extension are not robust structures and the fixing of them to the unit is minimal. I attach little weight to the small amount of detachment that would be required to allow the unit to be removed. In my opinion the appellant has not demonstrated, on the balance of probability, that the unit is a building or structure as it remains reasonably mobile.