We are designing a building for a client that will use purchased steam and chilled water from a local central plant. The central plant still has R-11 chillers and we advised them they needed a phase out plan. The client has engaged a third party to prepare a study of two phase out alternatives; replacement and retrofit. Can anyone provide guidance as to the level of effort required by USGBC/GBCI in the study of the feasibility of refrigerant phase out in order to claim exemption from the pre-requisite? At the surface it seems like it won't be hard for the client to squirm out of this pre-requisite.