This was a building in N.E. Portland used to broadcast a television station (Trinity Broadcasting) some years ago. They wanted, or were required to have an entry that met A.D.A. specifications.
This aluminum ramp system is pre-manufactured by Pemko Mfg. Co.. You need only do your math correctly as it relates to the height of the incline to be achieved and the consequential distance required to meet ADA rate of incline, and order the components accordingly from Pemkos Modular Ramp Assemblies. The various components are then cut to length as needed and fastened in place. As you can probably see, the installation of this wheelchair ramp required that the door be cut and a Pemko 216AV door bottom shoe installed.