On the Vidanta site there are two different listings for 1 BR lofts. The listing under Grand Luxxe itself is what I refer to as a studio loft, which sleeps 2 adults & 2 children. That one is a single floor unit; they are all located in the lower floors of building 5 in Nuevo Vallarta. They trade down to a 2 BR Grand Mayan, a 1 BR Grand Bliss, a Grand Luxxe Junior Villa or Master room (the lockout studio of a 2 BR GL suite), or a 1 BR GL suite during the off months (April through December). That may vary depending on when the contract was sold.
The other type is listed as a 1 BR loft in the Residence at Grand Luxxe. Those sleep 4 adults and are 2 story ones in the upper floor of building 5, similar in layout to the 2 & 3 BR lofts in tower 4. I think of them as penthouse lofts because of the location. They trade down to anything in Grand Bliss and below, 2 BR GL suites, 2 BR GL spa suites, and 2 BR GL villas, as well as the studio lofts on a 2 for 1 week owned basis. The trading may vary based on when the contract was sold.