The benefits of sustainable site planning
It is interesting to observe that among the first projects to fully embrace the more sustainable or “green” building types, institutional—primarily educational—projects lead the way to LEED certification. But, until recently, very few of these more sustainable institutional buildings were hospital or healthcare related. The trend toward greener, more sustainable projects has been catching up with the hospital and healthcare community for some time.
In the years since the inception of the LEED program in 2000, the criteria has evolved from building systems to embracing more site and environmental characteristics, as well. We all know the three E's of sustainability: ecology, economy, and equity. As LEED has evolved, these three elements are being more fully embraced. But how do they equate with hospital and healthcare campuses?
Ecology:Sustainable planning and design must recognize the intrinsic value of nature and encourage the identification and preservation of high-quality habitats that can reconnect people and nature, as well as the preservation and restoration of natural processes.
Economy:Sustainable planning and design must recognize the need to eliminate waste, the evaluation of the full life cycle of materials, and the financial viability of a project.
Equity:Sustainable planning and design must recognize the impact of design decisions on human well-being, the responsibility to create relevant designs, and to provide for all communities. This, in turn, encourages the protection of public health, safety, and welfare, as well as promoting greenspace conservation.
Much has been written about the benefits of exterior natural spaces on human well-being, but how should planners and designers integrate the basic infrastructure required for today's hospital projects into a sustainable site plan that also incorporates natural areas or greenspace? What are the costs and long-term benefits of green site planning?
During the planning and design process, it is important to study ways to integrate sustainable elements, such as recycling materials, innovative stormwater management, sensitive site layout, native (or naturalized) landscape materials, and site lighting into a complete site package.
The process starts by selecting a facility site that is compatible with the land-use patterns and then using that site to dictate the layout of the facility, rather than trying to force a site to fit a given building (figure 1). Placement of the facility can take advantage of topography, prevailing drainage patterns, existing vegetation, access, view, and sun angles to create better passive solar conditions that save on energy usage. Existing canopy trees and/or natural areas on the site should be saved whenever possible. Existing vegetation and landscape can decrease heat-island effects around a facility. Construction costs can be lessened by working with the site contours rather than mass grading, which creates air pollution (dust), erosion potential, and ecosystem loss.
This aerial view of the Heart of Lancaster Regional Medical Center in Lancaster, Pennsylvania, shows how the facility was placed into the natural contours of the site. Photography by Kerry Blind, FASLA.
Stormwater management is a critical element in most projects, and it can also provide one of the best opportunities for integration into the landscape. For instance, on several of Ecos Environmental Design's new facility site plans, we work the parking bays into the natural contours of the site and separate the bays with a minimum 15-foot-wide median (figure 2). Each median contains a linear raingarden (bioinfiltration) that captures the run-off from the bay uphill of it. The raingarden is a wide trench that is excavated in the median and is filled with an absorbent soil mixture. In some cases, the raingardens are lined. A small, perforated pipe is laid in the bottom to take excess saturation away. The raingarden is then planted with species that can assist in water absorption, cooling of the parking lot pavement, and providing an aesthetic landscape treatment.
The parking lot bays drain at Heart of Lancaster Regional Medical Center drain into a linear bioretention system located in each median separating the bays. Note the lack of curb on the uphill side allows sheet run-off to enter the raingarden. This photo was taken immediately after a heavy rain. Photography by Kerry Blind, FASLA.
Another method of stormwater management consists of using pervious pavement materials (such as concrete or asphalt) within the parking bays to capture run-off and allow it to percolate into a depth of gravel below. This allows for both storage and water quality right within the parking lot. Additional parking, or even fire truck access around a facility can be accomplished with a grass-pave system that allows for vehicular weight, while also allowing for percolation of run-off and mitigating the need for extensive detention. Each of the systems described above can be used instead of the traditional pipe and catchment systems, although some collection may be necessary, particularly if one is harvesting the run-off in cisterns.
We have also used the raingarden concept to capture roof run-off in landscaped areas adjacent to the buildings (figure 3). We have used a number of methods to collect the roof leaders into manifolds that spread the roof run-off into the raingardens that can run around the periphery of the building and infiltrate the collected run-off into the ground, much like the parking lot situation described above. We have also taken this concept to the next level by collecting the captured run-off and condensate into cisterns for storage. The collected water is then reused as irrigation. In many areas, grey water can also be collected and reused in this manner.
This foundation planting at Woodward Academy in Atlanta is actually a raingarden (bioretention) that captures and infiltrates the roof run-off within the planters adjacent to the building. Photography by Kerry Blind, FASLA.
Green roof gardens provide another method of using natural systems to provide a “free” ecosystem service. We have successfully used green roof treatments such as a tray system or a planted installation to capture and mitigate roof run-off (figure 4). Normal rainfall is recycled within the system and, with the proper selection of plant species, can provide an aesthetic and educational feature.
This roof garden at Woodward Academy in Atlanta is a container system that recycles the roof run-off for this LEED-certified building. Photography by Kerry Blind, FASLA.
If it is determined through geotechnical studies that rock exists under the site and some removal is going to be required, there are a number of options to the wholesale haul-off of the blasted or excavated material. Limestone or similar rock can be crushed on-site and reused as base under the building or under pavement, saving the cost of importing base material (which had to be excavated elsewhere and trucked in). Granite materials can be reused within the landscape to create more interesting planting arrangements. Concrete or asphalt that may exist on the site can also be taken up and recycled during demolition. Many contractors have access to large mobile crushers that can be brought on-site to crush rock or concrete for placement as base. Asphalt can similarly be ground and recycled into paving, reducing the need for new materials.
The visual pollution of site lighting is also becoming a more recognized issue in sustainable design. Most parking lot layouts use large fixtures on tall poles to provide adequate and secure lighting throughout a parking lot or along access drives. Many locales, as well as today's LEED criteria, require fixtures that are either full cut-off fixtures or that meet a power density appropriate to the location. Many projects rely on the use of flow-intensity, shielded fixtures and curfew controllers to turn off fixtures in nonessential areas after a certain time. Pedestrian level fixtures can often be used to achieve the same lighting level and meet the requirements.
Social equity can be achieved on a number of levels. Many municipalities are now requiring facilities to locate bicycle racks near entrances. Walkway access from a hospital's main entry points to the nearest public street are often required for ease in reaching public transportation. These walkways should, of course, meet accessibility requirements. In some cases, we have had to provide a route through the hospital campus for the local mass transit for pick-up and drop-off of visitors and patients. We have even had to provide “parking” for Amish horses and wagons at one facility.
There are many aspects of sustainable site planning and design that can be incorporated into healthcare facilities that integrate site infrastructure systems into a cohesive and sustainable, yet highly aesthetic institutional campus. Many visitors do not know that the lovely landscape surrounding a facility also functions as stormwater management, or that the pavement they are walking on is recycled. But they may notice that the air is a little more breathable, the water is a little cleaner and the parking lot a little cooler. After all, isn't contributing to wellness what healthcare is about? HD
Kerry Blind, FASLA, is President of Ecos Environmental Design, Inc., an Atlanta—based consulting fi rm providing public- and private-sector clients with sustainability-driven landscape architecture, environmen-tal planning and design, community planning, and LEED certifi cation