The 'Coty Principle' refers to an assessment manager or Court being able to give weight to new laws and policies. It derives from a now well-known case of Coty (England) Pty Ltd -v- Sydney City Council (1957) 2 LGRA 117 and provides that weight may be given to a new planning instrument. It is considered and applied in a range of appeals. Thomas J summarises it well in Lewiac Pty Ltd v Gold Coast City Council [1996] 2 Qd R 266:

It would be extraordinary if a planning strategy which was well on the way to adoption, or even adoption with amendment, could be frustrated by developments created in circumstances where neither the Council nor the court could give any weight to the plan as it had so far emerged.

Essentially the principle provides that the new planning instrument should receive more weight the further advanced it is through the legislative path. That means that if the new planning instrument, such as a planning scheme or planning scheme policy, has undergone public exhibition period or is close to adoption it should receive considerable weight.

Consequently, a Council is entitled to take into account its proposed planning scheme when assessing a development application. If proposed development conflicts with the proposed scheme then a Council assessment manager is entitled to give substantial weight to its new document. Conversely, if the new scheme favours a development project, the Council ought to facilitate approval even if there is some conflict with the current scheme.