We are pursuing CSv4 for a project and using the prescriptive approach for Optimize Energy Performance. I need clarification on the AEDG Table definitions for 'Mass Floors' and 'Slabs-Unheated'. 

The project has one level underground (B1) which will be a conditioned space. Can you confirm if this basement level slab is considered a 'Mass Floor' and therefore needs to provide the R-12.5 continuous insulation or if it would be considered a 'Slab' (it's unheated) that wouldn't require insulation?

A small portion of the basement extends beyond the project floor area that resides above ground. Would that part of the B1 ceiling require continuous insulation between the basement and hardscape? 

I also need clarification on if the Level 1 floor/B1 ceiling would be considered a 'Mass Floor' or are the insulation requirements just limited to the Envelope floors (ie. B1 floor)?

Thank you!