PREVENTIVE CONSERVATION ICOM-CC 17th Triennial Conference 2014 Melbourne SIMON LAMBERT* Canadian Conservation Institute Ottawa ON, Canada simon.lambert@pch.gc.ca TANIA MOTTUS Canadian Conservation Institute Ottawa ON, Canada tania.mottus@pch.gc.ca *Author for correspondence KEYWORDS: storage, facility planning, space, preventive conservation, overcrowding, storage reorganization, museums, collections ABSTRACT Storage space is a major concern for most muse- ums all over the world, yet practical guidance to assess current space usage or future space needs may not be entirely adapted to the needs of non- specialized users. Six published storage space es- timation methods are reviewed, compared and tested on a sample storage area, revealing that further guidance to elucidate key concepts and reduce uncertainty is needed. Museum storage space estimations: In theory and practice INTRODUCTION Worldwide, most museums struggle with storage space; over 60 percent claim that space is insufficient to store their collection, and 25 percent claim that it is difficult or impossible to circulate within storage due to overcrowding (ICCROM-UNESCO 2011). Well-managed storage areas require a holistic approach of which space planning is only one element (ICCROM-UNESCO 2011–2014). Yet, overcrowding can aggravate existing risks or generate new ones: damage through handling, undetected pest infestations, theft or misplacement of objects, or ineffective emergency response. Overcrowding may also diminish a museum’s capacity to use collections for the benefit of society through learning, interpretation, exhibitions and research. Effective space management requires planning. As shown by the Canadian Conservation Institute’s (CCI) workshops on storage reorganization, estimating storage space is not straightforward. Museums with reduced resources who wish to assess space efficiency or understand the remaining ‘useful life’ of their space still feel that they must rely on external assessments. Some do-it-yourself guidance exists, but not all of it is easily accessible or in a ready-to-use format. This article explores the process of storage space estimation from the perspective of the end user, in this case a staff member without access to outside expertise. Six published methods intended for mixed collections are reviewed and compared by test subjects on a sample storage area containing 257 objects. Perceptions on space estimation were also collected by way of an online survey (224 respondents from 50 countries). This study aims to define key parameters for the development of additional tools for small- and medium-sized museums. WHY ARE MUSEUMS ESTIMATING STORAGE SPACE? Whether for internal purposes or for a larger project, the motives and objectives of museum storage space estimations are many, and may focus on an existing storage area, or look into the future at a new yet-to-be- defined space (Figure 1). PUBLISHED STORAGE SPACE ESTIMATION METHODS, IN THEORY Defining storage space requirements is a complex task because it involves translating into physical space certain factors that are inherently difficult to