This is interesting in regards to lawful use and buildings x
The Town & Country Planning Act 1990 introduced new criteria for the period after which enforcement action is not possible against a breach of planning control.
THE 4 YEAR RULE
Any building, engineering or other works which have taken place without the benefit of planning permission, and that have remained unchallenged by enforcement action for 4 years or more, cannot be enforced against. So the erection of a building which goes undetected for 4 years will be allowed to remain.
However, the use of the building may not.
THE 10 YEAR RULE
Any change in the Use of land and buildings must have existed for in excess of 10 years before it can be protected from enforcement action. Therefore you may have a perfectly adequate building but no lawful use for it.
Similarly, the ten-year immunity rule applies to breaches of planning conditions (4 years for breaches relating to the use as a single dwellinghouse). Any breach of condition that occurred more than 10 years before the date on which the Council first takes enforcement action against that breach and which has remained continuously in breach over that period may then benefit from immunity.
EVIDENCE
In all cases if challenged you will need to produce sufficient evidence to prove, to the satisfaction of the Council, that the breach has occurred for longer than the appropriate period, without significant changes or breaks in the period of use.
This is one reason for undertaking proper planning searches before you purchase a property or business. What may appear to be a well-established operation may not enjoy the benefit of a lawful planning permission and you could find yourself open to enforcement action if you cannot prove the position.
If you can adequately prove the breach then an application for a Lawful Development Certificatewill provide you with a tangible proof of lawfulness for the future.