Elevators are not required in places of public accommodation and commercial facilities that are less than three stories or that have less than 3000 square feet per story unless the building is a shopping center, a shopping mall, or professional office of a health care provider, or other type of facility as determined by the Attorney General. This exemption does not apply to buildings owned by public entities per ADA Title II or Federal Buildings, for which the ADA does not apply. In addition to clearance and hardware, there are other parameters for door approach. Varying degrees of maneuvering space is required, depending from which direction a door is approached. This is not terribly simple to keep in your head.
Compliant ramps have compliant handrails, landings, edge protection etc.
This is a bit of a trick question. An Architect designing a building is required to comply with all applicable codes and regulations. A building department, from which a building permit is obtained, does not typically check for compliance in detail. They may or may not pick up some non-compliant items. Therefore, in the real world, buildings do get built that are substantially compliant, but may not meet all requirements.