Lawful use or development certificates Q & A DCP Section 4.301
The amendments to secs.64, 191 and 192 of the 1990 Act, introduced on 27/7/92 (25/9/92 in Scotland), enabling the issue of a lawful use or development certificate (LDC), are an excellent starting point to understanding the scope of development control law, since their operation effectively sets the boundaries between;
(a) what is development requiring express planning permission i.e. needs a formal planning permission;
(b) what is development but enjoys a general deemed permission given by planning law and thus does not require express planning permission;
(c) what is lawful development having been in operation for a specified number of years and thus having obtained rights to continue without the threat of enforcement;
(d) what is unlawful development which is that liable to enforcement action by local authorities.