ACI collaborated with Industrial Hygiene firm in addressing the source of interior moisture contributing to substantial amounts of interior mold growth on 50+ year old military apartment housing. Interior moisture related to a number of current conditions, but was not related to water entry through the exterior walls. The structure had recently been through a renovation process consisting of single glazed window replacement with retrofit insulated windows and coating of the exterior stucco walls with an elastomeric coating system. The new window systems and elastomeric coating on top of decades of paint applications minimized the ability of the exterior walls to breathe. The renovation processes had resulted in inhibited air flow within the units, particularly the end units with large exterior wall areas. Remediation consisted of the addition of mechanical ventilation within units to help circulate air, along with tenant education on how to minimize interior moisture build-up.