Compacting, fully enclosed, floored combination multi-antechamber and ramp system for emergency and civil defense use providing, when expanded, means of ingress and egress for the general population including the infected, wounded and handicapped to and from buildings or other folding structures via portals to which its adapter may be securely attached or retrofit while passing through a series of two or more antechambers so as to prevent spreading contamination and allow for various decontamination protocols to be conducted in separate chambers. Compacting is achieved by modularity in some embodiments, and folding in other embodiments, in both framed and panel versions, providing important advantages for transport, pre-positioning, storage, and warehousing.