The invention provides an insulated pipe-in-pipe assembly comprising (a) at least one inner pipe, (b) an outer pipe disposed around the at least one inner pipe so as to create an annular space between the outer and inner pipes, (c) porous, resilient, compressible material disposed in the annular space, and (d) a remnant of a container that previously was positioned in the annular space and previously held the compressible material in a volume less than the volume of the compressible material in the annular space. The invention also provides a method for making such an insulated pipe-in-pipe assembly.