Snowman, Ann MacKayNeff, VerneOut of space in the stacks and off-site, Penn State Libraries created a plan to completely reconfigure the layout of our Library Annex, comprised of four retrofitted facilities housing 1.6 million volumes, to achieve 20-25 years of growth space using only our ingenuity and the ILS. Learn how an idea developed into an inventory management system that is integrated with our catalog and the circulation system. Our system tracks empty space, allows us to perform targeted searches, apply mass updates, and run custom reports on our collections shelved off-site. Piloted in 2016 and implemented in 2017, the project is ramping up to full production mode. Over the course of the next seven years, off-site shelving will be completely transformed from a pseudo-shelf list arrangement to a high density tray system and will incorporate new modes of storage. Shelving will be replaced with compact tray shelving in one facility to maximize storage capacity.Presentation