In the 2010 ADA Accessible Standards, doorway requirements are found on Section 404 Doors, Doorways and Gates (Page 217 of The ADA Companion Guide). Some scoping requirements are also found in Section 206.5 Doors, Doorways and Gates. In summary, here are the technical requirements for doors:
1) Revolving doors should not be part of the accessible route. That means that you need a swing door alongside it if you want to use a revolving door.
2) Double leaf doors should have one active door at
with 32" minimum clearance (unless a power assisted door with stand-by power is used, then the entire width of both leaves are counted together)
3) Minimum clear widths are 32". Hardware (such as panic hardware) can decrease the width by 4" if mounted between 34" and 80" high (except closers that can be mounted 78" a.f.f.)
4) Maneuvering clearances follow figure 404.2.4
5) Recessed doors are allowed but only 8" max. of recess. A recess door could be found in music practice rooms which require ticker walls, or deep entry doors (see figure below)
6) Ground surface at door maneuvering clearances should slope no greater than 2% in any direction.
7) Thresholds at doorways shall not exceed 1/2" in vertical height. Note photo below is a brick threshold that is 1 1/2" high.
8) Door hardware hall have a shape that is easy to grasp with one hand and does not require tight grasping, tight pinching, or twisting of the wrist to operate.
9) Door hardware should be mounted no higher than 48" a.f.f. except in secured areas like pool gates where you can mount up to 54" a.f.f.
10) If a door has a door closer, then the sweep period of the closer shall be adjusted so that from an open position of 90 degrees the door will take at least 5 seconds to move to a point 12 degrees from the latch, measured to the leading edge of the door.
11) Interior and sliding or folding doors must have a maximum required opening force of 5 lbs.
12) At the bottom of the door, from 0"-10" above the ground there should have a smooth surface like a kick plate as shown below
13) Vision lights should be mounted 43" a.f.f. max to the bottom
14) Automatic and power-assisted doors can be used when the required maneuvering clearances are not able to be provided (like 18" on the pull side of the door) as long as they have stand-by power. See more detailed explanation below.