Ironstone Group

Indow, based in Portland, Oregon, specializes in manufacturing interior window inserts that enhance energy efficiency and comfort in both residential and commercial buildings. These inserts effectively block drafts, reduce noise by up to 70%, and can lead to significant savings on heating and cooling costs. Unlike traditional window solutions, Indow's products are easy to install and remove, requiring no mounting brackets, making them a non-destructive option for improving underperforming windows. The company offers a range of insert grades tailored to various needs, including soundproofing and UV blocking. With nearly 1 billion single-pane windows in the U.S. alone, Indow targets homes built before 1950 and has identified a substantial addressable market worth over $12 billion. More than half of its revenue comes from customers seeking soundproofing solutions. Indow's unique approach combines aesthetics, performance, and ease of installation, setting it apart from competing window insulation products. The company is actively developing new product lines to further streamline customer ordering and expand its market reach.