36 CFR Part 1191 ADA and ABA Accessibility Guidelines for Emergency Transportable Housing Units

405.2 Slope (Exception 2)
405.6 Rise (Exception)

These sections contain the technical requirements for the running slope and rise of ramp runs. The running slope of ramp runs must not be steeper than 1:12 and any ramp rise must be 30 inches maximum. The floor level of emergency transportable housing units is typically elevated 36 inches above the ground. To comply with the technical requirements, entry ramps installed at emergency transportable housing units with mobility features must have at least two ramp runs and an intermediate landing between the ramp runs. The entry ramps occupy 158 to 180 square feet depending on the landing configuration.⁴⁴ The final rule adds exceptions to the technical requirements that permit a single ramp run with a slope not steeper than 1:10 and 36 inches maximum rise where existing physical or site constraints would prohibit the installation of an entry ramp complying with the slope and rise requirements at emergency transportable housing units installed on private sites provided by the occupant of the unit. The exceptions reduce the area occupied by the entry ramps to 120 square feet. The exceptions may enable disaster survivors with disabilities who need emergency transportable housing units with mobility features to have the units installed on their private home sites where existing physical or site constraints may otherwise prohibit the installation of an entry ramp complying with the technical requirements at the unit. Many individuals with disabilities have difficulty using ramps with slopes steeper than 1:12 and may find entry ramps with a 1:10 slope not usable. Because individuals with disabilities have varying needs and capabilities, the concurrence of individuals with disabilities who will use the entry ramps should be obtained before using the exceptions.

^44. Where the ramp runs and landings are in a straight configuration, the landing is approximately 18 square feet. Where the ramp runs change direction at the landings, the landing is approximately 40 square feet.