"For the purposes of this Act uses and operations are lawful at any time if -- (a) no enforcement action may then be taken in respect of them (whether because they did not involve development or require planning permission or because the time for enforcement action has expired or for any other reason); and (b) they do not constitute a contravention of any of the requirements of any enforcement notice then in force."
"Where there has been a breach of planning control consisting in the change of use of any building for use as a single dwelling house, no enforcement action may be taken after the end of the period of four years beginning with the date of the breach."
"Unless there has been a clear cut change in planning circumstances such as a grant of planning permission for an alternative use, the introduction of another use incompatible with the original use or an indication of a deliberate intention to abandon the original use, then the use will survive throughout the ten years."
"The rationale of the immunity is that throughout the relevant period of unlawful use, the LPA, although having the opportunity to take enforcement action, has failed to take any action and consequently it would be unfair and/or could be regarded as unnecessary to permit enforcement. If at any time during the relevant period the LPA would not have been able to take enforcement proceedings in respect of a breach (for example, because no breach was taking place) then any such period cannot count towards the rolling period of years which gives rise to the immunity. It was for the land owner to show that at any time during the relevant period enforcement action could have been taken."
" . . . there was some presumption of continuance in planning law in respect of a use which had commenced as a result of a material change of use but which had ceased to be an active use before any accrued planning right had arisen."
"(21) Mr Lee acquired the site in 1996 but did not live in the building straight away. Indeed, for two or three years the mobile home on the site and the barn appeared to have provided residential accommodation for several people at various times, sometimes both being occupied and occasionally neither. This erratic pattern of use probably accounts for the various observations of the site recorded by the Council, and possibly the failure of the appellant's agent to refer to residential use in planning applications and letters during this period. However, once initial repairs were carried out the barn appeared to have been fitted and available for residential use from then onwards. The Council acknowledges a residential use from 2000 to the present day. There is no substantial evidence that since Mr Colby's occupation the barn was used for any purpose other than residential, except from time to time for minor storage connected with the use of the site as a whole. (22) I have taken into account Miss Champion's evidence and the lack of reference to the residential use in some planning applications and correspondence. However, during part of the relevant period, the appellant had a difficult and complicated personal life and I accept that these factors affected both his use of the site and the control that he was able to apply to the work being carried out there. I have no doubt that the barn was in full time residential occupation 1995/6 and again from 2000. In the period 1997 to 1999 the evidence indicates substantial work on the barn to complete its conversion for residential purposes, as well as on the remainder of the site. The appellant and several other people were involved in this work and frequently slept in the barn for substantial periods. I am aware of no evidence of any intention to abandon the residential use of the barn. Indeed, the main intention appears to have been to improve it to allow for full-time occupation as the appellant's home. (23) I have borne in mind the meaning of residential use described in paragraphs 18 and 19 above, and the failure to occupy a building for a period with no other reason being introduced does not often mean that residential use has ceased. I conclude on the balance of probability that residential use of the barn as a single dwelling house began more than four years prior to the date of submission of the LBC application and has continued since then without significant break."
"I accept Mr Corner's point that an enforcement notice can lawfully be issued notwithstanding that at the moment of issue the activity objected to is not going on -- because it is the weekend or the factory's summer holiday, for instance. The land would still be properly described as being used for the objectionable activity. However, I would reject Mr Hockman's submission that enforcement action can be taken once a new activity which resulted from the material change in the use of land has permanently ceased. I accept that there will be borderline cases when it is not clear whether the land is being used for the objectionable activity. These are matters of judgment for others."
"If, on the other hand, the deputy judge intended to suggest that an enforcement notice could and should be served in respect of a use which had commenced as a result of a material change of use in breach of planning control but which had ceased to be an active use before any accrued planning right had arisen, then I am unable to follow his reasoning or to see how an enforcement notice could be appropriate in those circumstances. It is important to keep in mind that an enforcement notice must specify the steps which the local planning authority required to be taken 'or the activities which the authority require to cease', for the purposes of remedying the breach -- see section 173(3) of the 1990 Act. There is, I think, force in the editorial comment at [1999] JPL 461, 471, that, if the deputy judge is to be taken to suggest that the notional continuation of a use which had ceased to be an active use before any accrued planning right had arisen could be sufficient to establish its own lawfulness: ' . . . this would mean that a local planning authority might have to issue an enforcement notice to require the sleeping use to stop: this would surely be a nonsense.' (59) The "nonsense" can be avoided by recognising that the deputy judge did not intend to suggest, in the Panton and Farmer case, that there was any need to serve enforcement notice in respect of the use which had ceased to be an active use before any accrued planning right had accrued."