The invention provides a sheet material comprising bicomponent filaments having first and second polymer components that are arranged in substantially distinct zones within the filaments, with the first polymer component formed of a relatively lower melting polymer and the second component formed of a relatively higher melting polymer. The filaments of the nonwoven fabric layer are densely arranged and compacted against one another to form smooth, substantially nonporous opposite outer surfaces, and the nonwoven fabric layer are calendered such that the lower melting sheath polymer is fused to the contacting surface portions of adjacent filaments to impart strength and coherency to the nonwoven fabric layer. The sheet material has excellent breathability and liquid barrier properties and may be useful in house wrap, medical garments, and envelope applications.