Davenport, IA Windows, Siding and Doors Davenport, IA is one of the four cities that makes up the Quad Cities. It’s the 3rd most populated city in Iowa with 104,589 residents. We love helping Davenport and Quad Cities residents with their window, siding and door needs. We’ve been serving the Midwest for almost 50 years with our quality products, expert installation and excellent service. Over 500,000 homeowners have trusted Feldco with their home improvement projects.