What is the total number of art storage facilities in the world? If possible, please provide an estimate of how many pieces of art are stored within these facilities.
Information on the items you requested is scarce, but if the number of art storage service providers is assumed to be not far from 281, the number of listings in The Clarion List's storage category, it is possible that the number of art storage facilities worldwide is around 1,038. Given that a 5,000-square foot facility can contain 10,000 artworks according to Crozier Fine Arts, it is also possible that the 189 art storage service providers in The Clarion List with more than 20 employees have 94.5 million artworks stored in their facilities if the facilities are halfway utilized.
NUMBER OF ART STORAGE FACILITIES
While we typically use sources published in the past two years, we found that there is very limited information on the subject. We, therefore, expanded our search to include older sources. According to an article published by The Wall Street Journal in 2007, "fine-art storage is a growing segment within the entire self-storage field, an $18 billion-a-year industry comprising more than 50,000 storage facilities nationwide providing more than two billion square feet of space." With this information, we can safely assume that, in 2007, the number of art storage facilities in the United States was less than 50,000 and their corresponding total area was a fraction of 2 billion square feet.
In June 2017, it was reported by international art magazine Apollo as well that demand for art storage has soared. Both Crozier Fine Arts and Cadogan Tate were cited as examples of art storage service providers that have remarkably grown in terms of square footage. The following month, Storage World reported that the United States, the United Kingdom, and Asia have self-storage facilities totaling 48,500, 1,430, and over 7,000, respectively. This means that there are at least 56,930 self-storage facilities worldwide. Given that art storage is considered a segment of self-storage, it is likely that the global number of art storage facilities is below 56,930.
The directory you provided, The Clarion List, proved helpful in identifying sample art storage service providers. We attempted to find similar directories but was unable to find any. Given that The Clarion List considers itself the "leading online resource to discover top rated art service companies worldwide," it may be the best starting point for determining the actual number of art storage providers and, consequently, the actual number of art storage facilities. Any serious art storage service provider would want to be listed on the directory.
There are 452 listings in the "Art Transport, Storage & Installation" category but only 281 listings in the "Storage" sub-category. Of these 281 listings, 53 listings have more than 20 employees, 12 listings have 11-20 employees, 8 listings have 6-10 employees, 5 listings have 2-5 employees, and 1 listing has 1 employee. It appears not all listed companies have provided details about the number of their employees. Of the 79 listings with employment details, 67.1% have over 20 employees, 15.2% have 11-20 employees, 10.1% have 6-10 employees, 6.3% have 2-5 employees, and 1.3% has 1 employee.
The reason we have noted this distribution is that the number of employees may be indicative of how large a provider's art storage service is. For example, based on a sample of three companies, it appears art storage service providers with more than 20 employees have storage facilities whose total area is no less than 500,000 square feet. Crozier Fine Arts has seven storage facilities that total to more than 700,000 square feet in area, UOVO has three storage facilities totaling to 520,000 square feet, and Artex Fine Art Services has five storage facilities totaling to more than 500,000 square feet. In contrast, the three sample companies in the cohort with 11-20 employees have only one storage facility each, and the square footage of each facility ranges from 6,000 to 140,000 square feet only. While the number and size of storage facilities of providers in the cohorts with 6-10 employees, 2-5 employees, and 1 employee, respectively, are not publicly available, there is a good chance that they each have only one storage facility.
If we assume that the actual number of art storage service providers worldwide is close to 281, we can roughly estimate the number of art storage facilities as follows:
1. Of 281 art storage service providers, 67.1% have over 20 employees, 15.2% have 11-20 employees, 10.1% have 6-10 employees, 6.3% have 2-5 employees, and 1.3% has 1 employee. This translates to the following figures:
Over 20 employees — 189 art storage service providers
11-20 employees — 43 art storage service providers
6-10 employees — 28 art storage service providers
2-5 employees — 18 art storage service providers
1 employee — 4 art storage service providers
2. If we assume that providers with more than 20 employees have five storage facilities, on average, and the other providers have one facility each, we can arrive at the following estimate of the number of art storage facilities:
(189 x 5) + ((43 + 28 + 18 + 4) x 1) = 1,038 art storage facilities
This is a very crude estimate, of course, given that The Clarion List is not an exhaustive list of art service providers worldwide and that averages were used for determining the number of facilities in each cohort. A more accurate number could be found if each of the 281 listings is researched; however, such approach would not be feasible given the time allotted for a single Wonder request.
NUMBER OF ARTWORKS STORED IN ART STORAGE FACILITIES
After researching several art storage service providers, we have made the observation that they do not disclose the number of artworks stored in their facilities. Some providers reveal the number of storage facilities they have and the corresponding square footage of these facilities.
Crozier Fine Arts, one of the key art storage service providers, believes that a storage facility with an area of 5,000 square feet can house 10,000 objects or artworks.
If we assume that each of the providers with over 20 employees has a total square footage of 500,000 and this square footage is fully utilized, we can roughly estimate that the 189 providers in the cohort have a total of 189 million artworks in their storage facilities. If the level of utilization is only 50%, the number would be 94.5 million.
((189 x 500,000) / 5,000) x 10,000 = 189 million artworks
((189 x 500,000) / 5,000) x 10,000 x 0.50 = 94.5 million artworks
These rough estimates are not yet inclusive of the artworks stored by providers in the other cohorts. Unfortunately, there is not enough information to estimate the numbers for the other cohorts. The square footages of the providers in the cohort with 11-20 employees are too diverse, and those of the providers in the rest of the cohorts are not publicly available.
There is limited information on your requested data, but a rough estimate of 1,038 art storage facilities worldwide was arrived at using the assumption that the actual number of art storage service providers is close to 281, the number of listings in the storage category of The Clarion List. Key storage provider Crozier Fine Arts believes a 5,000-square foot facility can house 10,000 artworks, so there is a possibility that the largest art storage service providers, those with more than 20 employees, have around 94.5 million artworks stored in their facilities if facilities are halfway full.