The document outlines the top 10 most common home defects according to the National Association of Certified Home Inspectors Chicago Chapter. The top defects include issues with foundation drainage, electrical systems, roofs, heating systems, plumbing, structural damage, water infiltration, crawlspace/attic ventilation, non-inspected construction defects, and installation defects. Many of these defects can lead to expensive repairs or structural failures if left unaddressed. Proper maintenance and hiring licensed contractors can help prevent major issues.