~ gate security/separate construction/contractor entrance = more time getting to the house
~ people who are sometimes incredibly anal/formal/picky, so budget more time on cleanup/setup. You do not want the foot of your 14' A frame knocking an $8,000 vase off a coffee table. You will also more than likely need a helper.
~ speaking of furniture, plan on moving or covering up a lot of stuff. Unless it's a huge bookcase or Steinway baby grand, move it (or have them move it), and bill accordingly.
~ plan on working around pets. They are their KIDS, YOU are the guest. Dont expect them to move/lock up their pets for you.
~ Make SURE the fans you install have the color of blade they want visible facing down. Every single one will have a lighting kit to wire up as well.
~ Make sure you program the dip switches or one remote could operate multiple fans in different rooms.
Condo attics here typically have an entryway hatch w/no stairs. No attic lighting. No floorboards (good).
If it is a high ceiling, you may want to go with remote switching; getting a switchleg to the location they desire can be all but impossible w/o cutting open finished walls. Existing switchplates may be wood or brass or something else non-standard, so if they want your additions to match, you need to know what they have.
If they buy the fans, hopefully they will have also purchased the correct (optional) downrods and light kits.
This time of year isnt too bad in attics, but I always buy the old work fan brackets that can be installed from below. Also, if the ceiling is anything other than drywall, plan on spending some extra time on it.
Bid the entire job as a whole, and if they want more, schedule another trip later to do it.