Tomorrow’s cities will need to perform better than today’s, and the challenges of the coming decades demand high performance design. To meet these challenges, designers (and their clients) have assembled a host of ambitious goals for urban projects—from encouraging smart transportation to protecting wildlife, from remediating toxic sites to building diverse neighborhoods—and increasingly, landscape projects are sold on such claims rather than their formal or aesthetic value alone.
As landscape projects become more daring and complex, how do we ensure the quality of our work? How can landscape urbanists speak authoritatively about innovative strategies and experiment at the scale of our interventions? How can we ensure that our projects perform as advertised? The essays in this issue explore the ways in which performance is being understood, advertised, evaluated, and communicated by a range of disciplines involved in the creation of better-performing cities, parks and neighborhoods.
Image by Nicholas Pevzner
Digging deeper into sustainability
It is time for landscape architecture and landscape urbanism to actively join the conversation about sustainability and the impact of urban development. While architecture has gone through much of the growing pains of developing a nuanced vocabulary for talking about sustainability, moving from vague generalizations about “green” projects and products, towards the development of clear and peer-reviewed methods for evaluating comparative environmental impact, landscape architecture and urban design have yet to fully engage in a process of critical reflection and acknowledgement of the impacts of our designs.
When we speak about performance, what data backs up our claims? Designers should be able to make at least a rough calculation of the impact of their decisions while the design is still flexible, rather than only being able to evaluate their designs once all decisions have already been made. While there is a great deal of information about products and materials, complex design decisions will always require balancing multiple goals, variables and constraints. Often the right decision is not immediately apparent.
For example, people are often shocked when they learn that some landscapes are constructed over acres of polyurethane foam. Yet, with more and more landscapes being built atop structure, over buried roadways, on pile-supported pier, or over parking garages, foam may be an economic solution to creating large variations in topography. Is foam any worse than using thousands of pounds of concrete to further reinforce a structure to bear heavier soil loads? Is it worse than excavating and transporting that much more soil? In order to critically compare options—be they related to material selection, structural systems, project siting, or management regimes—we need to decide what types of performance and impacts we care about.
All landscape projects are impactful to some degree—looking green and using plants does not make a project inherently sustainable. The design, construction and maintenance of all landscape and architecture projects consume energy and carry embodied carbon, water and human health impacts. How will the newfound urgency within the landscape profession to quantify and measure these impacts change the way we collaborate, execute projects, and talk about our designs?
Designers have begun to partner with experts who are capable of judging the impact and performance of design interventions, using sophisticated methods such as iterative energy modeling, Life Cycle Assessment (LCA), or dynamic systems modeling. Using an LCA, for example, one might compare the life-cycle energy expenditure, carbon footprint, or ecotoxicity associated with the manufacture, shipping, installation and disposal of polyurethane foam over the lifespan of a project, to the excavation, transportation, and eventual demolition and hauling away of a larger amount of soil and concrete. Designers should be able to evaluate the impact of their design decisions not only in terms of first cost, but also in terms of their material, ecological, economic, and social performance over time using measures that are specific to their project.
Reengineering our cities in sustainable and innovative ways will require increased scientific research to validate techniques and to more fully understand the scalar effects of urban interventions. Still, the most robust list of best practices and green strategies cannot replace the intelligence of design. The challenges of climate change, population growth, dwindling natural resources, increased human consumption and the need to radically improve the quality of life of large populations will not be met by a single strategy. Blanketing cities in green roofs or covering the landscape with algae farms will not solve all of our urban problems.
While general research in green infrastructure technology and practices will play a large role in shaping policy, opening up markets, and increasing the quality of specifications, the design community has a critical role to play in the field of applied research. Increasing our nimbleness in parsing data so that it can inform design decisions, and creating the necessary feedback loops for us to continue to learn from our designs once they are built, are essential steps in moving towards research-driven design at all scales. How will the newfound urgency within the landscape profession to quantify and measure these impacts change the way we collaborate, execute projects, and talk about our designs? There is much work to do.
New partnerships, integrated practice
Urban landscapes are complex and poorly studied. While landscape architects routinely transplant natural systems onto compressed urban sites in new combinations, urban landscapes do not perform like their natural counterparts. Designers increasingly turn to ecologists for expert opinions on ecological scenarios for which no definitive data exists. How can designers operate with confidence, avoiding paralysis even when scientific understandings of urban ecological phenomena are still very much in flux? Urban restoration ecologist Lea Johnson and landscape architect Renee Kaufman each tackle this question and pose new ways to operate within a field of uncertainty and continuous inquiry.
In an age of climate change and carbon footprints, there has been increased emphasis on valuing and calculating ecosystem services. Still, for projects to succeed over time, they must meet the diverse needs of the communities they are designed to serve. A project will not be sustainable unless it is taken care of, used, and loved. All landscape projects negotiate social, economic and environmental considerations during their design, construction and maintenance.
In writing the High Performance Landscape Guidelines, the New York Parks Department grappled with balancing these diverse considerations in order to prepare the city’s 29,000 acres of landscape projects to best meet the needs and aspirations of a 21st century green metropolis. In “Social Performance: Prototyping User Behavior,” Michael Miller looks at how designers and planners can better understand the potential of existing sites studying user behavior and prototyping future design interventions. Focusing in on the ecological and cultural relationships between plants and people, Peter Del Tredici challenges landscape architects to look closely at underappreciated spontaneous urban plants to better understand their role in the urban environment.
Despite its many limitations, LEED has become a well-accepted way of certifying building performance, widely transforming the way in which architects, builders, developers and clients evaluate projects. Recently, Sustainable Sites Initiative and LEED ND have emerged as rating systems for addressing the specific concerns surrounding landscape and neighborhood-scale projects. As these schemes have yet to mature and become widely used, practitioners have forged ahead in crafting tools that better meet their needs. In his article in this collection, Christian Runge discusses the process and motivations behind Mithun’s evolving set of customized performance metrics for districts and neighborhoods, while Mona el Khafif proposes recalibrating the goals and parameters of zoning to address the consumption/production of energy, waste and water.
In order to address multidimensional considerations and overlapping spatial and temporal concerns, designers will rely on a range of analytical tools for generating and evaluating design. Some of these tools, such as systems modeling, come from emerging fields such as industrial ecology, while others, such as analytical sectional drawing—are native to designer’s training and draw on our unique disciplinary strengths.
Ari Bain and Eva Gladek propose an integrated design methodology that merges research and iterative modeling in order to develop a high performance permaculture greenhouse that challenges conventional approaches to food production and distribution. While their Polydome model represents a highly sophisticated data-driven methodology that recognizes the deep complexity of the constructed urban landscape, designers can also express this richness through techniques of drawing. We posit that the deep section—one which brings together design elements, site conditions and ecological processes in a single drawing—allows designers to interrogate the interrelationship of distinct elements and flows in space and time.
If landscape urbanism aspires to take a leadership role in driving urban change and improving the way our cities perform, we must be prepared to ask the tough questions required to feel confidant in the quality of our proposals. The diverse approaches and perspectives collected in this issue seek to expand the tools available for addressing the critical problems of designing tomorrow’s cities.
Nicholas Pevzner is a designer at Michael Van Valkenburgh Associates in New York City. His work explores the role that infrastructural landscape moves can play in structuring and sustaining healthy cities. Nicholas received his Bachelor of Architecture from the Cooper Union in New York in 2005. He later received his Master of Landscape Architecture from the University of Pennsylvania in 2009, where he has also been a visiting lecturer and critic in landscape architecture.
Stephanie Carlisle is a designer and environmental researcher at KieranTimberlake Architects in Philadelphia. Her research focuses on the relationship between the built and natural environment and employs interdisciplinary design methodologies and data-driven modeling to study complex urban systems. Stephanie holds a Master of Architecture from the Yale School of Architecture and a Master of Environmental Management from the Yale School of Forestry and Environmental Studies. She is a co-editor of this issue.