In a recent legal case, the 'building' in question comprised two limestone piers which had been Grade II listed in 1986. Mr Dill came into ownership of the piers but did not appreciate that they were listed. The items were sold and exported, and Mr Dill applied unsuccessfully for retrospective listed building consent to remove the items from the list.
However, the removal of the piers had come to the attention of the local planning authority, who required their reinstatement. Mr Dill appealed to the Secretary of State on the ground that the items were not 'buildings', so that no consent was required. The planning inspector held that it was not open to him to go behind the fact that an item appeared on the list as a listed building. Mr Dill then appealed to a judge but without success.
If an item is on the list of historic buildings then it is a 'building' even though, to a layman, it doesn't look like a building.
There have been many other legal cases where something looks obvious but the legal definition has to be looked at very carefully to decipher what it really is.
For example, under the Leasehold Reform Act, the tenant of a house has the right to buy the freehold. There have been court cases when the owner of the freehold has argued that what the tenant owned was not a house but a flat or commercial premises. It must be a building reasonably considered a house, divided vertically from any adjoining house. Even a block of flats can be legally defined as a house if the tenant has a lease of all of the building.