I spoke to my contact in our Planning & Development Team and he has supplied the following information.
A vexing question and one that has no 1 answer.
Refunds for development applications are handled case by case and really relates to the degree the application has been assessed.
For instance we have a refund level relative to the stage the application is up to in the IDAS process. If the application is only at “application stage” the refund may be 80%, if at the “information stage” it may be 70% and so on. If at decision stage there may be no refund.
I know it is not too structured but refunds also tend to be a bit of a negotiation between us and the applicant.