2 Layers of 5/8" Drywall in Garage Side
Garages are to be separated from single family residences by 1/2” gypsum board on garage side ONLY, provided the garage does not open into a sleeping room. (See 2017 edition ICC Table R302.6.)

Also the door between the garage and house shall be a solid wood door a minimum of 1 3/8” thick and is not permitted into a sleeping room. (See ICC R302.5.1.1.)

However, town houses require 2 hour separation, which requires 2 layers.