The final appeal raised two issues. The first concerned whether an applicant for an approval to erect wind turbines first needed a licence under the 1989 Act and, whilst having potentially very wide practical ramifications in Scotland, was essentially a matter of statutory construction of limited wider legal interest.
The second ground however concerned a condition attached to the consent which was arguably lacking in an enforcement provision. Whilst the Court rejected the challenge on the basis of its reading of the condition in the context of the permission read as a whole and rejected the analogy with planning jurisprudence, it did give some important although obiter guidance to the issue of the implication of conditions in planning permissions. This part of the Court's Opinion is likely to be of much wider import and will have implications for all planning practitioners.
Both Lords Hodge and Carnwath who gave the only fully reasoned Opinions concluded that there is no complete bar on implying terms into the conditions in planning permissions. Whilst not doubting the restrictions to which material can be had regard to when interpreting a permission, as set out in cases such as R v Ashford Borough Council, ex p Shepway District Council 1999 PLCR 12, both Judges distinguished between interpretation and implication and concluded that as a matter of principle "While the court will, understandably, exercise great restraint in implying terms into public documents which have criminal sanctions, I [Lord Hodge] see no principled reason for excluding implication altogether." All other members of the Court agreed.
The court went on to reject assertions in cases such as Trustees of the Walton-on-Thames Charities v Walton and Weybridge Urban District Council (1970) 21 P & CR 411, Salmon LJ at p 418 and Widgery LJ at p 420, and in the Sevenoaks District Council case (above), Sullivan J at para 45, that there can never be an implied condition in a planning permission as too absolute.
Furthermore Lord Carnwath rejected the view of planning control as an interference with property rights requiring to be kept within narrow limits. He considered that it was not consistent with the modern approach, and there was no reason to exclude implication as a technique of interpretation, where justified in accordance with the familiar, albeit restrictive, principles applied to other legal documents. Likewise, whilst it must also be borne in mind that planning conditions may be used to support criminal proceedings and those are good reasons for a relatively cautious approach, such considerations arise from the legal framework within which planning permissions are granted. They do not require the adoption of a completely different approach to their interpretation.
Finally, it referred to but did not doubt the first instance English cases on tail-pieces Midcounties Co-operative Ltd v Wyre Forest District Council  EWHC 964 (Admin) and Hubert v Carmarthenshire County Council  EWHC 2327 (Admin) and appeared to accept that it was not lawful for conditions to be capably altering the nature of the approved development but concluded it did not do so in the case before them.
James Findlay QC of Cornerstone Barristers appeared for Mr Trump.