BUILDING SYSTEM PERFORMANCE

Buildings are more than just a collection of individual pieces that have been assembled in one place. Many of the building components are part of a larger system. In fact, it is best to think of a building as an integrated group of interdependent systems. For example:

• The HVAC system relies on the envelope of the building to limit infiltration of outside air.
• The cladding relies on the rigidity of the structural frame to keep it from bending and cracking.
• The roof relies on the strength of the framing to prevent it from being lifted off the building.
• The structural frame relies on the cladding and the roof to keep it dry and prevent its deterioration.

Defects in a building component occur when the design is faulty, when the installation is wrong, or when the components are designed by different disciplines unaware of other disciplines’ design requirements.

The failure of a part of the building often means that a building system failed. Proper investigation of a failure in building performance should consider the possibility that a defective component is related to a more comprehensive defect. This raises the following questions:

• What is the defective component?
• How does that component relate the rest of the building?
• Does the performance of the defective component depend on the performance of other building components or building systems?
• How did the building system fail to perform?
• What actually caused the performance failure?
• How does the suspect building system compare to similar installations in the industry?
• Who was responsible for the proper design and installation of a building system?
• Could the failure have been foreseen and avoided?
• What must be done to rectify the problem?