Articles/Publications
The Civil Engineer’s Role in Going “Green”
By Nicole Holmes, PE, LEED® AP
Today, our society seems to be increasingly aware of the detrimental effects decades of intense development have caused to our environment. High gas prices, global warming, water pollution, and urban sprawl are some of the problems we hear about frequently. In response to these problems, the building industry is being transformed by the movement to go “green,” and new building projects (both public and private) are being constructed to exemplify environmental stewardship. As civil engineers, we have the ability to play a vital role in this “green” movement by integrating sustainability into our designs and understanding the tools used to measure “green” design.
The United States Green Building Council (USGBC) developed the Leadership in Energy and Environmental Design (LEED®) Rating System to develop a means to measure sustainability for new building projects and major building renovations. The LEED® Rating System addresses sustainability in six major categories: Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, Indoor Environmental Air Quality, and Innovative Design. Within each category, sustainable design goals are defined in a series of “credits” measured by a system of points. Sustainable design projects following the LEED® Rating System can earn Certified, Silver, Gold, or Platinum ratings depending on the number of credit points the project achieves.
Although many of the credit points under the LEED Rating System relate to architecture or mechanical building systems, approximately 28% of the available credit points are in the Sustainable Sites and Water Efficiency categories. Designs for these categories either fall under the scope of the project’s civil engineer or require close coordination by the civil engineer with other team disciplines. Since many of the LEED® credits can be influenced at the earliest onset of a project, particularly with the selection of a site, having the civil engineer involved with the project from the very beginning is important.
The major goal of the Sustainable Sites and Water Efficiency categories is to minimize a project’s adverse impacts to local ecosystems and natural water bodies. According to the USGBC, buildings affect ecosystems in a variety of ways, including loss of habitat, increased stormwater runoff, erosion and sedimentation problems, reduced water quality, heat island effects, light pollution, increased vehicle use, greenhouse gas emissions, and depletion of natural aquifers.
To meet the goals of a sustainable site, the civil engineer should work with other disciplines (such as the landscape architect, architect, and mechanical engineer) to develop an “integrated,” green design that minimizes adverse impacts to natural systems. For example, civil engineers can help to guide the team’s decisions during the design by tracking and managing the amount of impervious surfaces proposed for a project. Impervious surfaces directly increase the amount of stormwater runoff from a site, reduce groundwater recharge, reduce stormwater quality, and increase heat island effects. Civil engineers can help manage these negative impacts by promoting the use of permeable paving materials and/or green roofs, and promoting Low Impact Development Techniques such as “greening” (transforming impervious surfaces to pervious surfaces).
There are countless ways in which civil engineers can demonstrate environmental stewardship and play a major role in the current movement to “go green.” By understanding tools such as LEED®, we can help our clients effectively achieve the goals of sustainable design.
Published in BSCES Newsletter, November 22, 2006