Abstract: A resiliently-mounted through-foundation pipe coupling is provided that is suited for building plumbing applications. The resiliently-mounted coupling assembly is a length of straight plastic pipe preferably with pipe couplings on each end. The combined length of the pipe and associated couplings is selected to roughly match the thickness of the foundation. The combined pipe and associated couplings are covered with and bonded to a relatively thick layer of foam rubber elastomeric material. The combination of pipe and elastomeric layer is placed in the desired position in a foundation form before the foundation is poured. The elastomeric layer cushions the plastic pipe from the forces of being cast in place as the foundation is poured, and also provides resilience to the eventually installed piping system (connected to the through-foundation pipe fitting) against the motion of back-filled soil, and against alignment forces and mechanical loading of attached plumbing.