When it comes to designing and maintaining high-performance buildings, ensuring that a structure is both air-tight and water-tight is paramount. These two elements are fundamental in maintaining the building’s structural integrity, energy efficiency, and overall durability. Air-tightness refers to the ability of a building to prevent uncontrolled air leakage, while water-tightness ensures that no moisture can penetrate, causing potential damage over time. The significance of air and water tight cannot be overstated. Buildings that are not properly sealed can face several issues such as energy loss, mold growth, corrosion, and structural damage. Both air-tightness and water-tightness are crucial to maintaining a controlled indoor environment, ensuring the comfort of the occupants while reducing the overall energy consumption.