Hello, Many years ago, the SLA Geography & Map Division developed standards for University Map Collections. I think that they included information on aisle widths, but I could be wrong. The articles on the standards can be found at: Selmer, Marsha L. 1988. "Standards for university map collections: the rationale, history, and method." Bulletin (Special Libraries Association. Geography & Map Division) no. 152: 10-18. Special Libraries Association. Geography and Map Division Committee on, Standards. 1986. "Draft standards for university map collections." Bulletin (Special Libraries Association. Geography & Map Division) no. 143: 7-14. Special Libraries Association. Geography and Map Division Committee on, Standards. 1987. "Standards for university map collections." Bulletin (Special Libraries Association. Geography & Map Division) no. 148: 2-12. Special Libraries Association. Geography and Map Division Committee on, Standards. 1985. "Standards for university map collections; section B: collections." Bulletin (Special Libraries Association. Geography & Map Division) no. 140: 2-3. There were some space considerations raised in Leighton's book on planning libraries, but if I remember correctly, that was only for how much space was needed for staff areas, not aisle width. Leighton, Philip D. and Weber, David C. 1999. Planning academic and research library buildings. Chicago, Ill.: American Library Association, Linda Zellmer -- Linda Zellmer Government Information & Data Services Librarian Liaison to Natural Sciences & Agriculture 415 Malpass Library Macomb, IL 61455 [log in to unmask] Phone: 309-298-2723 <callto:309-298-2723> Fax: 309-298-2791 <callto:309-298-2791>