HANOVER — Dartmouth College is moving forward with plans to upgrade and expand its off-campus library storage and service facility on Etna Road in Lebanon.

The Dartmouth Board of Trustees over the weekend approved spending $100,000 to complete the designs for a new standalone building, which Dartmouth said would “address an urgent need for increased offsite storage and provide room for collection growth over the next 15 years.”

The current library storage facility, located in part of a former factory Dartmouth owns at the 11-acre site at 56 Etna Road, is full, according to the Dartmouth website. The new 20,000-square-foot standalone building, expected to cost $18.5 million, would house the Dartmouth library’s “low-use print collections and college records,” Dartmouth said. It would be able to store 1.2 million books and 35,000 “record units” and free-up space in Baker-Berry Library, according to Dartmouth. Pending permit approvals from the city of Lebanon, construction could begin as soon as next summer, Dartmouth said.