The Sustainable Campus: Working With Nature
- By Peter Gisolfi
- June 1st, 2010
Sustainable practice in architecture and landscape architecture refers to an exacting point of view, one that values natural processes and natural systems over individual human interventions. To put it more simply, a project — whether a building, a landscape, or a campus — might be described as sustainable if the final implemented plan minimizes negative impact on the natural environment and on natural systems, and maximizes the opposite; that is, the plan supports or mimics natural processes. Put even more simply, the sustainable plan would cause the least possible harm to nature and would work in concert with natural processes to the greatest possible extent.
From the point of view of sustainable practice, a campus is a group of buildings and a landscape that operate together. When we connect sustainability to the idea of campus planning, it is essential that we look at the broader picture; not only at the impact of each building, but also at the impact of a collection of buildings and a collection of landscape interventions. Basically, we ask, how does the whole system function? How does it impact and interact with the natural environment?
The success or failure of a particular campus in terms of its sustainability can be quantified. Campus planners might consider, for example:
- How much energy is consumed by the campus?
- How much energy is generated on campus?
- What is the carbon footprint of the campus?
- What is the stormwater impact of the campus?
- What percentage of the campus acreage is covered in vegetation?
- How much of the vegetation resembles a self-sustaining, natural landscape?
- What is the total impact of the campus landscape on larger, natural systems?
It has been argued persuasively that so-called green architecture is fundamentally flawed because most of the decisions related to environmental impact are made before the architect even begins to design an individual building. This argument maintains that patterns of settlement or urban patterns themselves have more impact on nature and the environment than the potential impact of any individual building. Thus, the campus is a useful model for sustainable practice. It is not simply a building. The campus is a group of buildings, a series of landscapes and, in fact, an overall landscape that can be seen as a pattern of settlement that may function in a sustainable manner or may be coaxed to function in a more sustainable way.
Understanding the Buildings
The buildings on a campus should be understood collectively. By addressing the following issues, campus planners can begin to identify the aspects of the campus that can be made more sustainable:
- What is the total number of buildings, and what is their total area in square feet?
- What is the occupancy of the buildings? How many square feet are there on campus per student, and how many square feet per person (student and staff)?
- What is the total energy consumption of all the buildings, and what is the energy consumption per person (student and staff)?
- What are the larger common systems that provide energy to the buildings on campus? (e.g., lake water cooling at Cornell University)
- How much energy is generated on the campus?
One of the most common ways to evaluate buildings in terms of sustainability is to calculate the energy consumption per square foot. For example, a report on a new green building might brag that it consumes only 40 percent of the energy of a comparable code-compliant building. The difficulty of this hypothesis is that a completely unnecessary building might be energy-efficient on a square-footage basis, but might be consuming energy unnecessarily if it were not needed or adequately occupied.
Understanding the Campus Landscape
The landscape can be understood as a system, and it can be evaluated quantitatively. Our purpose here is to understand how the surface and even the subsurface of the campus landscape function.
Evaluating the Landscape and the Buildings Together
- How big is the campus, and how does it relate to the surrounding landscape?
- What is the total area covered by buildings?
- What total area is covered by other impervious surfaces?
- What is the total surface area covered by pervious surfaces, such as natural vegetation, lawns, and playing fields?
- What amount of chemical additives is applied to the green portions of the campus, and how much water and electricity are consumed for irrigation?
- How does the campus landscape perform as part of the surface water system and as part of the groundwater system; basically, how does the campus function as part of the hydrologic system?
- What species and categories of vegetation are on the campus?
- To what extent is the green part of the campus landscape sustainable?
- How are automobiles, service vehicles, and public transportation located on the campus?
The campus can be best understood as a composite system of buildings, landforms, and surfaces that are evaluated and managed together. In the end, the system we want to influence is the overall campus, which requires that we address the following issues:
Putting Theory Into Practice
- What is the combined effect of runoff and infiltration from buildings and all land surfaces on the campus?
- A stormwater model of the total campus should be prepared.
- A combined energy model for the entire campus landscape and all the buildings should be prepared.
- What are the positive aspects of the buildings and the landscape on the campus? These might include self-sustaining buildings and landscape strategies.
- What are the negative aspects of the buildings and the landscape on the campus? These might include the heat-island effect of all the buildings and land surfaces, the pollution added to the stormwater sewage system, and the burden of storm sewage and sanitary sewage contributed by the campus.
Perhaps it is easier to understand these ideas by looking at one campus planning example. Several years ago, my architectural firm prepared a campus master plan for the College of Mount St. Vincent, an institution of 1,700 students with 800 in residence on the campus in the Riverdale section of the Bronx in New York City. In the fall semesters of 2008 and 2009, my students in the graduate program in landscape architecture at the City College of New York prepared new master plans for the same campus, based on sustainable ideas.
The landform itself is simple. It extends 1,400 ft. in a north-south direction along the east shore of the Hudson River, and extends 2,400 ft. in the east-west direction from Riverdale Avenue down a slope of about 145 ft. to the river’s edge. A simplified understanding of the landform would describe it as three plateaus separated by two steep slopes. The steep slopes (about 25 acres) are covered with woodland vegetation, while the flatter terrain (about 45 acres) is used for parkland, lawns, building sites, playing fields, and parking.
The buildings and impervious land surfaces cause erosion (mostly on the steep slopes) and excessive runoff, which empties directly into the Hudson River. The students determined that the stormwater model could be dramatically changed and restored to a more natural balance by reducing impervious surfaces, by retaining stormwater at various locations on the site, and by creating systems for recharging stormwater into the groundwater system.
The buildings themselves are old and have relatively primitive mechanical systems and inadequate insulation. The energy consumption of these buildings could be reduced by almost 50 percent with the implementation of elementary strategies, such as new mechanical systems, building management systems, and adequate insulation. In addition, on this relatively open site, there are significant opportunities for producing energy through cogeneration (recycling the heat from the generation of electricity), solar power, and wind power. The students concluded that a campus in this setting in New York City could, in fact, become energy independent over time.
Simple landscape changes would create more sustainable results. The playing fields could be maintained without the use of harmful fertilizers and pesticides, or could be replaced with synthetic turf fields that have no effect on the chemical balance of the site. The parking lots could become more pervious and could detain runoff beneath them; they could be shaded with new vegetation. They might also be selectively covered by trellises of photovoltaic cells, which create shade and generate electricity. The lawns and other vegetative areas could become natural meadows of “no mow” native grasses and wildflowers, and the trees gradually could become part of a self-sustaining “suburban” forest, which would act in harmony with the 25 acres of natural woodland. If these strategies were adopted, the amount of maintenance required on the campus would be dramatically reduced.
In summary, through a variety of techniques, these 70 acres in the Bronx could become an oasis that might produce as much energy as it uses and might cause no harm to the environment, while taking advantage of multiple possibilities offered by its unique physical geography.
The size, density, and physical geography of a campus determine to what extent it may become self-sustainable. The College of Mount St. Vincent example is felicitous because the approximately 480,000 sq. ft. of buildings on 70 acres is a relatively modest density, and the resources of natural vegetation and river breezes are beneficial. It is important to determine to what extent a particular campus might become self-sufficient. Can it be self-sufficient as an energy model? As a landscape, can it mimic a natural forest? Can it mimic native vegetation instead of being an artificial landscape requiring constant maintenance?
How does the campus function as part of a larger system? Does it pollute its neighbors? Does it receive unwanted stormwater from neighboring properties? Does it put a significant burden on municipal resources, such as water, sewage, and power? Understanding and modeling the wider system of the campus are the first steps in determining how the eventual transformed campus might be a positive contributor to the larger system.
The basic management strategies for a sustainable campus are to reduce energy consumption, generate energy, and approximate natural systems on the landscape. The choices of plant material should be based on native woodland species that do not require irrigation or chemical fertilizers. The surface of the land should become more permeable and should increasingly resemble more natural conditions. The stormwater system should mimic nature, and should not exceed the natural amount of runoff. Every opportunity should be seized to generate or collect energy on site, reduce energy consumption, and eventually turn the entire site into an energy-neutral environment. Once these strategies are put in place, the cost of maintaining the campus and the cost of energy for the campus will be reduced beyond your wildest dreams.
Peter Gisolfi, AIA, ASLA, is senior partner of Peter Gisolfi Associates, a firm of architects and landscape architects in Hastings-On-Hudson, NY, and New Haven, CT. He is chairman of the Spitzer School of Architecture at the City College of New York, and is the author of the book,
Finding the Place of Architecture in the Landscape.