This SpringerBrief presents strategies for fire mitigation based on combustible assembly systems of exterior walls. Providing background information on common exterior wall systems, the mechanisms of fire spread, and case studies, it examines the difficulties in controlling a fire with several materials and assembly methods. The brief compiles information on typical fire scenarios which involve the exterior wall, along with further exploration into test methods, approval and regulatory requirements for the various assembly systems. Offering testing approaches for possible mitigation strategies, the brief takes into account that current commercial wall assembly systems are constructed to improve energy performance, reduce water and air infiltration, and allow for aesthetic design flexibility. Exterior Insulation Finish Systems, metal composite claddings, high-pressure laminates, and weather-resistive barrier systems all have components which directly impact the fire hazard. Recommendations for future exterior wall construction are based on identified knowledge gaps.