I am constructing a home where the owner is having a complete living quarter installed in the basement for an older relative. Just needed to see if it required 5/8 drywall on ceiling. Also, wondering if the door going from basement steps to upper living area requires a fire rated door.
5/8" drywall is rarely required in single-family residences. It was used historically because ceiling joists are often 24" on center, and 5/8 resists sag.
You can certainly use no-sag 1/2" if you like. If your joists are 16" on center, standard half inch may be fine, by I don't know why you'd risk it for the minimal upcharge.
A fire-rated door is also probably not required. If this is a rental situation, check with your local building authority on both counts.
For single family and double family occupancies (duplexes), no Fire rating is required between units. So, no fire rated gypsum board, doors, etc. are required. (See ICC Chapter 3)
As of 2017 any tri-plex or larger requires fire separation AND fire sprinklers. (Yes, fire sprinklers...I can hear the groans from here.) The sprinklers can be “residential grade”, but they are required. (Residential grade allows you to feed each sprinkler head from the nearest water source, I.e.: kitchen sink, bathtub, etc. The sprinklers don’t need a separate water line into the house like in commercial projects.)
BTW, don’t forget the fire separation between the garage and this space, egress window from your new sleeping room and smoke detector at new sleeping room door.
John Six, are you from Toronto? If you are and are concerned about fire code for a rental, beware. For a relative it's totally fine to build it as a single family dwelling. If there is rent involved then the firecode is insane. In that case it's actually a double layer 5/8 x rated drywall (not the good x-rated, the fire resistant x-pensive kind) on the ceiling, and the walls if the neighbours are within 3', fire rated doors, alternate egress, separate HVAC systems and many other considerations. It's not uncommon for a 50k basement as a single family dwelling to jump to 150k. I currently have a job on hold because a guy wanted a 5 unit building reno and he didn't believe us (myself and the plumber) that it would cost 3-5 times of other projects he had done for single family. I'd recommend that you take as many precautions to protect from fire as is practical. But tread lightly when it comes to multi dwelling.