The invention includes a microbe-mitigating architectural barrier that includes a barrier forming material, and at least one biocide. The barrier forming material may be a bitumen product, an elastomeric polymer and combinations thereof. The microbe-mitigating architectural barrier may be formed by applying an emulsion composition directly to an architectural surface, or it may be preformed and adhered or otherwise secured to the architectural surface in the form of a sheet or film. The invention also includes architectural assemblies and/or building envelopes that include the microbe-mitigating barrier. Related methods are encompassed within the scope of the invention. Such methods include a method of preparing an architectural barrier that includes: (a) preparing an emulsion that comprises a barrier forming material chosen from a bitumen product, an elastomeric polymer and combinations thereof, and at least one biocide, (b) applying the emulsion to at least one architectural surface, and (c) drying and/and or curing the emulsion to form a barrier.
