The green view of cities is to treat them like ecosystems where growth and decline are cyclical. In the traditional view of cities abandonment of neighborhoods and empty buildings are driven by abstract forces like the economy, culture or our whims. What connects the two is us as opportunistic organisms. Like a crab leaving a shell to a snail, abandoned buildings and disused spaces are a vital feedstock—they are a second growth opportunity.

One marker of a healthy city is how we reuse buildings and vacant land. Who decides which are left to crumble and which are converted to new uses? In the interstitial space between abandonment and when a developer recognizes their value, many artists and creative minds have done a great service to, for example, Cleveland’s old warehouses by moving in where no one else sees any value. In Germany, artists and designers are subsidized by the government to think big about reusing abandoned industrial spaces. In Cleveland, artists are usually the risk takers, willing to conjure new uses for big old warehouses and abandoned buildings so they can cheaply live and establish studios.

Efforts like Pop Up City are calling attention to how artists provide energy and ideas to buildings, vacant properties or whole blocks that can lead to temporary uses or permanent ‘adaptive reuse’ (artists can be agnostic about which is better). A project of the Cleveland Urban Design Collaborative, urban planner Terry Schwarz has programmed some decidedly irreverent events like last week’s Transportainment (pictured right), in partnership with Walk + Roll which called attention to the abandoned Here Here Gallery space in the heart of Playhouse Square with live music, urban gardeners cooking their food on hot plates, and even miniature horses. To the uninitiated, it might seem like a one-off, but it follows a pattern of rethinking abandonment in ‘shrinking cities’ from Dresden to Detroit. For example, see artist Gina Reichert and architect Mitch Cope, a Detroit couple whose start up shop Design 99 is buying foreclosed properties, giving them cool, high design extreme makeovers and selling them to their artist friends. It’s the Millennials’ answer to sustainable living.

Last February, the Urban Design Center flew Berlin artist/designers Klaus Overmeyer, Tore Dobberstein and Andreas Haase to Cleveland for a workshop on temporary use projects, such as adaptively reusing pieces of the industrial landscape, as a way of drawing new energy to urban areas. This uber hip assemblage presented some of their projects including temporary sports facilities or "sportification" for urban sites. Participants took a trolley tour of several neighborhoods and talked about ideas for temporary use projects for specific sites.

In "Pop Up City”, UDC’s second book in its Infill series, Overmeyer, Phillipp Oswalt and Philipp Misselwitz explore how temporary uses happen.

Vacant spaces in cities are vast and plentiful, if poorly maintained. “Urban spaces lie fallow from time to time during the transition from one use to another, a process in which the periods of ostensible disuse in fact possess strategic significance.” To whom? you might rightfully ask. “Generally not by longtime residents but by newcomers, people whose lives are in a state of flux…young entrepreneurs and hatchers of schemes who use an urban niche as a springboard for the realization of an idea. With little starting capital, a concept can be tested and then, if is successful, firmly established and further expanded. In other words, temporary use offers a low entry threshold and possible avenue for the potential establishment of an economic, cultural or social concept.”

Temporary Users as it were are attracted to areas that have walk-in potential or that have striking architecture. Unlike developers, they don’t require ‘strong bones’, great views, or even any semblance of a real estate market. While they’re looking for buildings and spaces that are suitable to them and their ideas, some factors like infrastructure, proximity and places to organize are more likely to give rise to temporary uses.

The essay and book is not only a fascinating read, it’s filled with eye candy – from pop ups to DIY-craftshow-inspired graphics and postcards with photos from Pop Up City events, like Leap Night (the Feb. 29, 2008 temporary use of The Flats filled with a bonfire, snowboard ramp, a performance stage, a ‘bear’ and a ‘dead Christmas tree’ garden featuring dead Christmas trees Schwarz saved from treelawns) and Bridge Mix where a disused pedestrian bridge in Tremont became the site of storytelling, dancing, a ‘living room’ installation, star-gazing among a swirl of activity. In the backflap is a great resource for Temporary Users, an advice booklet with how to navigate city permits and find free stuff while not squelching the alternative spirit.

Schwarz writes about the CUDC, an organization, leading this charge until individuals pick up the mantle. Choosing The Flats, for example, was an intentional nod to corporations that unaffiliated Temporary Users may not choose to do.

“We do this openly and unapologetically because the economic environment in Cleveland is brutal and it is in the public interest to support private sector investment in the city,” she writes in her chapter titled, Ad Hoc Urbanism. “Pop Up City was conceived as a way to circumvent the negativity and shift the discourse about shrinking cities from scarcity and depletion to regeneration.”

Will those seeds grow to inspire some Temporary Users to leave the protective circle of the CUDC? Time will tell. In the meanwhile, Schwarz isn’t under any illusion that Pop Up City solves the underlying chronic problems of crime and poverty. “Cleveland also needs experiments and diversions to reinforce the piece of the city’s soul that remains embedded in the physical fabric of this place, and temporary events that ignite a desire for lasting change.”