A faced building insulation assembly includes a first facing forming a first major surface of the assembly with a central field portion having one or more spunbond continuous polymeric filament mat layers. Preferably, the facing is fungi growth resistant and has a selected water vapor permeance rating as applied to an insulation layer of the assembly. The facing may also include one or more polymeric film layers, a fungi growth inhibiting agent, a pesticide, and/or a heat activated bonding agent that bonds the facing to the insulation layer of the assembly. The insulation assembly may also include a second facing forming a second major surface of the assembly that has a water vapor permeance rating equal to or differing from the first facing.