Design features of buildings are important factors in the movement of fire and smoke within a building and the ability of firefighters to conduct suppression operations and remove smoke effectively. Building obstacles that make ventilation difficult allow smoke to accumulate and obscure firefighters’ vision. Windowless buildings and basements present difficult circumstances for firefighting operations and make smoke removal difficult as well (figure 9.1). Designers should take design issues into consideration and take actions to mitigate problem areas during the design phase of a building project. Building designs that lack natural ventilation or ventilation built into the building HVAC system allow for the accumulation of dense smoke and intense heat, which hamper firefighting operations and endanger building occupants who may become trapped in the building. One of the most important firefighting tactics for suppression of a fire is the venting of smoke and hot gases from a building so that suppression operations can be accomplished efficiently and safely. Building designers need to be conscious of important ventilation functions and design an effective means of venting smoke and hot gases from a building through the use of the building HVAC system or a dedicated smoke exhaust system. NFPA 204, Standard for Smoke and Heat Venting, should be consulted when designing buildings. Once a building is completed, building owners or managers should see that firefighters are trained in the use of building HVAC, smoke venting, control equipment, and operational controls.