Baseline Envelope NonResi/Resi U-Values

Our project is a multi-family residential project (8 stories) and we have modeled the baseline roof as a Residential, Insulation Above Deck U-Value per Table 5.5-1. We have received a LEED Review Comment back stating that "Note that the residential area must comprise 60% or more of the space usage for this building in order for it to be classified as a residential facility. If the project cannot be classified as a residential facility based on the definition provided, revise the roof constructions in the Baseline model " We have seen several opinions posted on LEED User in how to model Non/Resi Envelopes: (1) To model all residential floors with Residential U-Values and to model all non-residential floors with non-residential u values (2)To model all residential zones with Residential U-Values and to model all non-residential zones with non-residential u values I have never seen this reference of 60% when discussing the classification of Non-resi/Resi U-Values. (I have combed through Addendum and CIRs). We have 59% of floor area devoted to the apartment units. The remaining area is corridors/ MER/ storage, amenities and based on the LEED Review comment would need to update our Baseline Roof to non-Residential. Does anyone know if there is specific language in Appendix G or USGBC documentation which states how Non-Resi or Resi is determined?