Educating Subcontractors Posted on August 02, 2019 in Pella Windows & Doors of Omaha and Lincoln Pella Windows and Doors of Omaha & Lincoln educates subcontractors every year on the newest products and latest installation techniques. We've built relationships with several dozen subcontractors who have professionally installed thousands of our doors and windows in buildings from small single-family residences to multi-story historic buildings. Click on the video above to find out more!