With each new project, architects, landscape architects, engineers, and other design professionals are being asked to provide solutions that are sustainable, meet criteria for low-impact development (LID), and provide holistic environments that enhance the social, psychological, and economic aspects of a community as well as the living systems of the earth. As designers, our ability to turn existing man-made or “grey” infrastructure into “green” infrastructure can assist in achieving these holistic goals.

The Center for Green Infrastructure Design (CGID)¹ defines green infrastructure as “an interconnected network of natural and social systems that provide a diverse range of environmental, cultural, recreational, psychological, public health, and economic benefits.” The CGID states that “green infrastructure conserves environmental values and functions, sustains clean air and water, promotes a sustainable economic regional framework, and contributes to the health and quality of life for our residents.”

The new International Green Construction Code (IgCC) as well as LEED® and SITES™ criteria provides a framework of standards that focus on achieving green infrastructure for projects.

The IgCC code establishes minimum green requirements for both new and existing buildings and includes sustainability measures for the entire construction project and its site starting with the design and going through construction to the certificate of occupancy and project commissioning. The new code is looking to address the built environment from a holistic perspective, making buildings more efficient, reducing waste, and creating positive impacts on health, safety, and community welfare.

The LEED for Neighborhood Development (ND) criteria will expand the LEED criteria beyond the building envelope and the immediate site and will provide criteria for sustainable neighborhoods. LEED ND categories of Neighborhood Pattern and Design and Green Infrastructure and Buildings provide credits in areas that stress heat island reduction, tree-lined and shaded streets, building energy efficiency, building water efficiency, stormwater management, and recycled content in infrastructure.

The guidelines and benchmarks for The Sustainable Sites Initiative or SITES™ present nine categories with standards for protecting and restoring hydrology, soil and vegetation, repairing damaged ecosystems and resources, minimizing the effects of construction, and supporting and maintaining sustainability.

These new codes and criteria provide a framework for designers as they work to achieve green environments. However, urban areas present many challenges towards the creation of a green environment. This article will highlight some recent innovations that help achieve and sustain green infrastructure within the framework of man-made (grey) infrastructure and will review current trends and materials that help to recapture and enhance urban green space, enhance urban arboriculture, enhance water quality and reduce stormwater runoff, achieve energy efficiency, and overall, integrate sustainable design solutions for bridging the building-site (grey-green) interface.

At 5c Studios in Tempe, Arizona, green façade systems or green walls provide a building-site interface to improve urban air quality and building energy efficiency. Photo courtesy of greenscreen®