The HH "area" consists of Buildings 11-14, 23-26. There are certainly other areas near HH, including the elevator buildings (62-64), but they are not presently included in that definition.
IMO, 11-18, 62-64 and 23-29 are all close enough to HH to be locations close to Olivia's, the main pool, etc and even there, I don't find that to be important since you can easily get to the HH area by using any bus from any area of the resort.
Buildings above #30 are in the Turtle Pond or South Point areas (plus the already mentioned 62-64). Buildings above #30 all have a second access to the master BR in 1BR villas - buildings 11-29 have access only thru the bedroom.