Lately it seems as though these two words have been getting a lot of attention. One newspaper article touts the success of a recent “certified” Green Building; the next touts the million-dollar budget overrun of a planned Green Building. So what, exactly, is a green building, and how can you “think green” without seeing red?
“Green Building” is both generic and specific. In its most general use, a Green Building is one that is environmentally-friendly; that is, it uses a lot of natural lighting, the engineered systems are energy-efficient, the materials used for construction are recycled, etc. More specifically, however, it refers to a building that meets the rating criteria under LEED — Leadership in Energy & Environmental Design, a program of the U.S. Green Building Council. The LEED Rating Program evaluates buildings in six categories (see sidebar), each with specific prerequisites as well as credits for various attributes. The lowest level for a LEED green building is “Certified,” followed by designations of “Silver,” “Gold,” and “Platinum,” depending upon credits earned. According to the U.S. Green Building Council, “LEED is a self-assessing system designed for rating new and existing commercial, institutional, and high-rise residential buildings. It evaluates environmental performance from a ‘whole building’ perspective over a building’s life cycle, providing a definitive standard for what constitutes a green building.”
Buildings earn points for meeting such criteria as building re-use, brownfield or urban redevelopment, water efficient landscaping, energy efficient building systems, recycled materials, specification of locally-manufactured products, building siting, use of natural lighting, and more.
It is important to note that a building cannot automatically be LEED-certified. There is an application process and accompanying fee. However, just because a building is not LEED-certified does not necessarily mean it is not a Green Building. In fact, many buildings meet the minimum criteria for LEED certification; however, no application has been submitted for the certification.
The challenge with building green is to match initial cost with life cost. There are many “green features” within a building that add no cost and, in fact, are quite typical for any project. An example of this is proper site orientation for a new building in order to take advantage of solar conditions for natural lighting, heat gain, and/or heat gain minimization. Then there are those features that add a moderate cost, but can lead to long-term cost savings. An example of this would be operable windows and light monitors to reduce utility expenses, or highly durable finishes, which minimize replacement costs over the life of the structure. And finally, there are those features that come at a high initial cost, with a longer term payback. Thermal ice storage systems with heat recovery and “smart” facades are examples of this.
One of the keys to success in building green is a holistic approach; that is, looking at the architecture, interiors, civil, mechanical, electrical, and plumbing disciplines from a common “green” approach. This is also referred to as “Whole Building Design.” Not only must all the design disciplines coordinate regularly, but they must also buy-in to the necessary trade-offs required to make a project stay within budget.
Obviously, the Owner’s needs and budget are the driving force behind any project. Early in the pre-design stages of a project, the Owner and design team need to define “green building” goals. Feasibility and life cycle cost analyses may be needed to more accurately determine the trade-offs between initial costs and life costs. These studies do slightly increase the overall design-phase costs; however, in some cases they can be offset by grants and—even more importantly—can significantly reduce operations and maintenance costs during the life of a building.
As a full-service engineering firm, JDB Engineering has always endeavored to add value to our clients by designing cost-effective, energy efficient buildings. Three decades ago, we designed one of the earliest ice storage systems of its kind in the United States at the General Public Utilities facility in Reading, PA. We went on to design a number of additional ice storage systems, and were featured in “The Military Engineer” for our leading-edge energy efficient design capabilities. The concept is to produce ice at night in insulated tanks, then melt the ice during the day to provide building cooling.
One of the most important aspects of green design — but also frequently overlooked — is the life cycle cost implications of a project. In its most basic form, life cycle costs incorporate the operations and maintenance expenses for a building, including energy consumption. Using this benchmark, the life cycle cost of a building can be broken down as follows: design = 2%; construction = 34%; and operations & maintenance = 64%. The “Total Life Cycle Cost” model (TLC) goes a step further and incorporates the cost of the people and function of a given space. Under this scenario, planning, design, operations, and maintenance only account for a minimal 5% of the Total Life Cost of a given building. (Source: Carnegie-Mellon University, Center of Building Performance and Diagnostics.)
Regardless of the benchmarks, it is important to realize that a proper design can increase facility productivity from 5% to 30%. In addition to sound, energy-efficient design, post construction commissioning can also play a major role in the energy efficiency of a given building. At JDBE, we have commissioned a number of systems and buildings, and have routinely found that the automatic temperature control sequences and setpoints were not optimal for energy efficiency and cost savings.