Off-site Library Storage Solutions

by Charles Forrest

“Just-in-case” to “Just-in-time”

Libraries are responding to user preferences for online information access and changes in collection formats. Many are transitioning from “just-in-case” provision of physical items in on-campus storage to “just-in-time” access, combining online information use with a small on-site physical collection and delivery of back-up physical items from off-site storage facilities.

As a result, academic libraries are able to exercise responsible stewardship for important legacy intellectual assets, store general and special collections appropriately and free up valuable library space for alternative uses.  Libraries are reconfiguring space to enable new learning opportunities, celebrate evolving technologies for research and scholarship and create and sustain dynamic academic communities.

Off-site storage at Emory University

Storage Options

There are tried and true approaches to the storage of and access to physical information resources, both on-site within libraries and off-site in specialised facilities. These include:

  • Standard-height static or mobile shelving  [1]
  • High-density compact shelving[2] which may be manually or electronically operated
  • High-bay static shelving (Harvard model)
  • High-bay high-density compact shelving
  • Automated storage and retrieval

Standard-height Static and High-density Compact Shelving

Standard-height (66 inches [1.68 metres] to a maximum of 96 inches [2.44 metres]) static shelving is the typical way collections have been housed on-site in libraries, in both closed and more recently open stack collections with appropriate aisle space for access by users. Some of this shelving may be curved in its shape but more often is straight.

Use of standard-height high-density compact shelving has grown in recent decades, with the goal either to reduce the amount of space required for a physical collection of a defined size, or to increase the capacity of existing space to accommodate growth. With compact shelving, there is only one aisle for several or many ranges of shelving. Aisle contention may become an issue, particularly in high-turnover circulating collections. Compact shelving for public, open-stack areas offers active and passive safety features. Arrangement of collections in static or high-density compact shelving with open access is usually according to a subject classification to facilitate browsing by users.

Standard-height shelving, both static and high-density compact, has been used efficiently for off-site collections, particularly in spaces originally designed for human occupancy, with typical ceiling heights of nine to ten feet [2.7 to 3 metres]. While some off-site storage facilities maintain a classified subject arrangement, most use a running number order.

High-bay Static Shelving (Harvard model[3]) and High-bay Compact Shelving

Purpose-built off-site storage facilities generally incorporate higher ceiling and shelving heights. High ceilings facilitate the use of high-bay static shelving or high-bay compact shelving. Shelving heights up to 40 feet [12 metres] or more are not uncommon.  Books, bound periodicals and other items are typically stored in trays or bins, or metal or acid-free cardboard, and shelved by size, with no effort to maintain a classified arrangement and call number order to maximise the number of items stored in a given space. Trays or bins are loaded and retrieved using human intervention via a rolling ladder or mechanised lift. A separate online inventory system is often employed to track an item’s location by shelf number and bin number. Such an inventory system is typically linked to the integrated library system, to enable search and discovery, and to facilitate delivery of requests.

Automated Storage and Retrieval Systems

Completely automated systems are available where bins containing items are loaded on to and retrieved from racks, without intervention by a human operator. Retrieved bins are delivered to a central location where an operator takes the requested item from the bin, and prepares it for delivery to the requester. The bin is then returned to the first available space in the rack appropriate to its size. Items returned from circulation or use are loaded into the first available bin for return to the rack. The inventory control system can be programmed to optimise retrieval times by loading more frequently requested items into bins closer to the central location to reduce retrieval time. Such fully automated systems offer the highest storage density per volume of space and are often used for more frequently used materials and built at a central campus to ensure short retrieval times for effective service. Automated systems may also be located off-site.

Automated storage and retrieval, University of Utah

Process and Design

Factors that influence the choice of shelving and the design and operation of storage facilities include anticipated collection usage rates, desired turnaround times, costs of various construction and maintenance options, and long-term per-volume storage costs. Off-site facilities and service programs should ideally be built around the processes and needs of a particular community. The most effective off-site facilities are designed and built around user needs, workflow processes and the preservation of materials; they are not simply warehouses filled with shelving. The following table summarises various approaches to shelving systems on-site and off-site storage:

Table 1 Types of Storage and Characteristics
Type of storage Density/ Cost/


User Acceptance Retrieval time
On-site Open stack static shelving Low High High Short
Open stack compact shelving Medium High Medium/High Short/Medium
Closed stack static shelving Low High Medium Medium
Closed stack compact shelving Medium High Medium Medium
Automated storage and retrieval High Medium Medium/High Medium
Off-site High Medium Medium/Low Long
Standard-height static Low Medium Medium/Low Long
Standard-height compact Medium Medium Medium/Low Long
High-bay static High Low Medium/Low Long
High-bay compact High Medium/Low Medium/Low Long

Strategy and Partnership

An off-site shelving facility can support research and learning objectives directly through prompt delivery of requested materials and indirectly through releasing on-campus space for new learning spaces. Such facilities are often developed through cooperation or collaboration with partner institutions that have common or complementary needs, as well as through existing or new consortia. Collaborative approaches enable the sharing of resources and joint management of heritage collections. Successful collaboration depends on similar goals for the institutions involved, shared values, sustainable planning and strong leadership.

Systems and Operations

Environmental conditions

Mechanical and digital technologies are important for the successful operation of an off-site facility. Environmental conditions must be cool and dry for the long-term preservation of paper and other materials and vary from conditions for spaces intended for human occupancy. Sophisticated systems need to be designed, built, and maintained to ensure optimal conditions for different media—print-on-paper, microfilm and fiche, magnetic media, photographs and photographic negatives, motion picture film, leather bindings, framed art, and other materials depending on local holdings and collection interests.

Processing area during initial ingest, Library Service Center, Emory University and Georgia Tech, Atlanta, GA

Discovery and inventory control

The discovery layer of the local integrated library system (ILS) must provide robust and reliable access to the bibliographic records for physical items in off-site collections. The ILS must then interoperate with the off-site facility inventory control system to enable the placing of an item request, the generation of a “pick list” and the tracking of an item during the retrieval and delivery process all the way to the initial requester.

Preservation and conservation

Reprographics or scanning technologies are appropriate and effective ways to deliver online facsimiles of portions of printed works such as book chapters or articles in bound periodicals. Duplication of magnetic media such as audio and video tapes, and computer disks and drives can be used to provide access to content while preserving the original and to migrate analogue and digital information from unstable and deteriorating media to more stable and enduring formats.



Academic and research libraries acquire, organise and present the inscribed cultural record to support research, discovery, knowledge acquisition and learning. Libraries must protect investments in legacy intellectual assets both by preserving physical media in appropriate and affordable storage facilities and making embodied content available through a variety of physical delivery mechanisms and/or analogue and digital reformatting. Off-site storage facilities occupy an important niche in the emerging twenty-first century environment for teaching, learning, research and scholarship.

Additional Resources

Nitecki, Danuta A. and Curtis L. Kendrick (editors). Library off-site shelving: Guide for high-density facilities. (Englewood, Colorado: Libraries Unlimited, 2001).

A dozen-and-a-half chapters from academic library practitioners and others cover topics ranging from governance and cost, through facility planning and design, to move-in and management. Off-site collections have been a necessary operational component for many academic libraries and library consortia for decades. Fifteen years old but still worth a look.

Image Permanence Institute. IPI® is a nonprofit, university-based laboratory devoted to preservation research. The world’s largest independent laboratory with this specific scope IPI was founded in 1985 through the combined efforts and sponsorship of the Rochester Institute of Technology and the Society for Imaging Science and Technology. IPI provides information, consulting services, practical tools and preservation technology to libraries, archives, and museums worldwide. The imaging and consumer preservation industries also use IPI’s consulting, testing and educational services.

ReCAP (Research Collections and Preservation Consortium). ReCAP is  a preservation repository and resource sharing service, jointly owned and operated by Columbia University, the New York Public Library and Princeton University. Located on Princeton University’s Forrestal Campus, ReCAP cares for more than thirteen million items and fulfills some 250,000 requests for materials each year from its partners and from libraries around the world. The ReCAP website is worth exploring as a rich resource for information about a busy and innovative off-site service center.

[1] Terms to describe shelving are used variously throughout the world. Fixed, static or stationary are words used to describe shelving which is fixed in position. It is sometimes called cantilever shelving and may be made from metal or wood and used for display and storage. Some shelving units may be on castors and therefore considered mobile. Most shelving is modular and purchased and installed in components.

[2] High-density shelving is sometimes referred to as compact or mobile shelving.

[3] Lizanne Payne. Library Storage Facilities and the Future of Print Collections in North America.(Dublin, Ohio:  OCLC Programs and Research, 2007) p. 9 Viewed 13th November 2016

Author details:

Charles Forrest is Principal and Owner, 21CL Consulting and has thirty-five years of experience in academic and research libraries. Charles retired in May 2016 from the position of Director, Library Facilities, Emory University Libraries, Atlanta, Georgia. He held previous positions at Emory and spent nearly a decade with the University of Illinois libraries in Chicago and at the flagship campus in Urbana-Champaign. Charles is a member of the Standing Committee of the IFLA Library Buildings and Equipment Section.


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