Duo-Corp. was established June 1977 in North Lima, Ohio. The first and only product manufactured, at that time, was an aluminum basement hopper window. This original basement window was manufactured in a 5,200 square foot building by a production/office staff of four (4) people. Over the course of almost 4 decades, the business has expanded into a 70,000 square foot facility manufacturing several basement, utility and egress window products with single shift production capabilities of 1,500 units per day.
In 1984, the first vinyl basement window available to the window industry was produced - “The Aristoclass”. Tested by time and usage, “The Aristoclass” continues to be the premier vinyl basement hopper window sold in the United States window market.
In 1991, Duo-Corp. designed, manufactured, and marketed “The Patriot” and “The Competitor” vinyl basement hopper windows which have become two of the most recognized and used commodity basement windows in the industry.