Cooler over “Cool” Boulevards in Innovation Districts: Climate- and People-Centered Designs for Arid Climates
Limited areas of shade forces people to move through the corridor rather than encourage them to stop and linger.
Impervious paving surfaces increase overall temperatures.
Buildings designed with unglazed windows increase temperatures inside buildings.
Rather than focusing on creating “cool” places, planners should give far greater priority to creating cooler micro-climates. This means exploring techniques to measurably reduce temperatures and create habitable spaces for people to meet, linger, and connect.
Our research also found that two groups of people are often not invited to contribute to boulevard design, which helps explain the disconnect. The first such group consists of planners, ecologists, and climatologists with strong backgrounds in sustainable and ecological development. The second group is the community—the people who walk along these boulevards daily and have intimate experience with what is not working, and why. These voices are absent from many developments found in arid climates.
On the positive side, the research did identify several important people- and climate-centered design principles for districts in arid climates.
- Embrace pervious surfaces and natural vegetation: Vibrant streetscapes, which help create pleasant walking experiences, can be achieved through the use of natural materials for sidewalks and pathways. These materials can include small absorbent stones, paths adorned with vegetation, or even white-washed pavement. Dark and impervious asphalt surfaces dramatically increase temperatures because they generate significant levels of long-wave radiation (produced when the sun’s rays reflect off such surfaces). This simply means that the designers of such places should look to their natural ecology and materials to help create cooler solutions.
- Design in nodes: “To help reduce the effects of climate, we need to have nodal development,” explained professor Evyatar Erell of the Desert Architecture and Urban Planning group at Ben Gurion University of the Negev.4 He argued that the concentration of buildings, shading elements, and vegetation significantly reduces direct sun exposure and overall temperatures. A nodal approach, which is a compact form of development, can be applied to a linear boulevard by developing areas of concentrated focus along the boulevard. This would mean creating strategic areas that have denser clustering—of trees, shading elements, buildings, or other treatments—to “hold” greater numbers of people in creatively cooled conditions.
- Rethink the design of buildings and their connections to each other: Buildings with large overhangs create welcome areas of shade for at least part of the day and should be encouraged. Heavily glazed windows also cut down on reflection of the sun’s rays, reducing the level of sun radiation into buildings. Buildings along boulevards commonly have large glass plate windows on the ground floor and first floor, making careful treatment of windows a priority. In a suggestion complementary to the nodal development described above, researchers Mazouz and Zerouala observed that designing narrow streets to connect buildings is recommended for desert locations to reduce the level of sun exposure, even at a cost of limiting the movement of air. This is contrary to warm and humid locations, where planners should focus on increasing airflow while providing shade.5
- Change hours of access: The use of intelligent responsive lighting—which enables luminaires to be programmed to switch on, or to change in brightness or color, depending on the time and public usage patterns—enables people to participate in activities at dusk and after dark, avoiding the hottest hours of the day.
Large building overhangs create new areas of shade and places to rest.
Natural surfaces and local vegetation create a cooler micro-climate.
Nodal development—in some spots—provides space for people to congregate.
In 1984, researcher Oke argued that what climatologists require is an “ability to demonstrate the importance of climatic information in the design of a settlement, and the predictive power to foretell the climatic impact of alternative design strategies.” 6 Today, the imperative to combine climate-focused design with innovation- and people-centered developments is paramount. Inviting input from thought-provoking researchers and practitioners, such as Evyatar Erell, and from the broader community, is the only way to get there.
3 Gerald Mills, “Progress toward sustainable settlements: A role for urban climatology,” Theoretical and Applied Climatology 84 (2016): 69–76.
4 Interview with Evyatar Erell, BGU professor, The Desert Architecture and Urban Planning Group, May 2019.
5 Rohinton Emmanuel, “A hypothetical ‘shadow umbrella’ for thermal comfort enhancement in the equatorial urban outdoors,”Architectural Science Review 36 (1993): 173–184.
6 Timothy R. Oke, “Towards a prescription for the greater use of climatic principles in settlement planning,” Energy and Buildings 7 (1984): 1–10. 1984.