If it only says "$20/sf/yr", and nothing else, there's not enough info to tell if the $20/sf is just the base rent (a net rent number), a gross rent (all inclusive), or a modified net of some kind. In retail in my market, for example, you will 9 xs out of 10 see numbers quoted as $20/sf NNN - the "NNN" after the number tells you that the $20 is for the base rent and there are triple net charges or "extras" (typically CAM, tax, insurance) in addition to the base number. Also, what complicates matters is different people sometimes define "triple net" differently. At the end of the day, when you call to ask what the asking rent is - also ask "what type of lease is it?"; "what are the extras?"; and "can you breakdown what they are for me?"
Jan 20, 2010