In summer, temperatures in Phoenix, Arizona, can climb to 107 degrees Fahrenheit. Part of the swelter is due to naturally arid conditions in the Sonoran Desert, but man-made influences like the urban heat island effect–a phenomenon caused by concrete and asphalt in cities absorbing and retaining heat–also play a role. The Environmental Protection Agency estimates that in cities with populations over 1 million people (Phoenix has about 1.5 million residents) temperatures can be anywhere from 1.8–5.4°F warmer than surrounding rural areas during the day and up to 22°F warmer at night.
To combat the heat island effect–which can lead to higher energy use from people cranking up the air conditioner to cool off inside and dangerous conditions for those outside–the EPA recommends planting trees, building green roofs, using alternative paving materials, and planning cities differently. Meanwhile, the Phoenix-based architecture firm Blank Studio recently developed a heat-island-busting concept which employs a few of those ideas, but takes them to a radical next level by suggesting a sculptural rope canopy be draped over seven miles of downtown Phoenix streets, creating partially shaded boulevards beneath them. The design was done in response to an AIA competition, as Dezeen reports, to help beautify Phoenix, make the city more livable, and generate more public space.
Compare a hot summer day spent on a city street to one spent shaded under a tree. The former is typically a blistering sweaty mess, but the latter is pretty pleasant. When Blank Space hatched its conceptual plan, it kept that effect–of sunlight filtered through leaves–in mind. “A Japanese word, komorebi, describes the ephemeral dappling of sunlight beneath a tree canopy,” the firm writes in a description of the proposal, which it calls Jacaranda Avenue. “We asked what could happen if this dappled shade condition was generated over large swaths of this Sonoran Desert city.”
The studio describes the project elegantly: “This cloud-like fabrication would reduce the initial intensity of the sunlight by more than half,” it writes in its creative statement. “Not a rigid canopy, the form becomes more reminiscent of a field of swaying grasses or the kinetic sculptures of artists Ned Kahn or Christo + Jeanne-Claude.”
The canopy is only half of Blank Space’s overhaul of Phoenix’s urban fabric. The second part involves remaking the streets into car-free, pedestrian-friendly avenues through which only public transportation can travel. The firm envisions plantings irrigated with gray water from surrounding buildings. “Comfortable, walkable public space now contains the amenities of urban life: cafes, playgrounds, sculpture gardens and art displays, markets, film screenings, and so on,” the firm writes.
As a whole, Jacaranda Avenue reads like an urbanist’s pipe dream, since a project like this would require substantial policy interventions. But however far fetched, the design shows how canopies–a favorite typology for architects to explore–could be deployed at a scale to make streets and public space more hospitable in desert cities.