"Greening" a Profession
The Supply Side
The popularity of green building has also been gaining momentum because of increased knowledge by architects. Design publications have begun to highlight green buildings more frequently. Renzo Piano and Norman Foster, in receiving the 1998 and 1999 Pritzker Architecture Prize, were recognized for their completely integrated design solutions, often called high-performance buildings or green design.
Although the foundations for green design are just beginning in the U.S., examples are multiplying. Over time, the true value of these buildings will be studied, quantified, and proven for benefits such as increases in productivity and learning ability and decreases in absenteeism and cancer.
NBBJ Takes the LEED
I am captivated by the potential for leadership in this area. The possibilities for improvement should be ever-expanding and thus part of the concept of best practices. Here are some initiatives and projects now underway at NBBJ:
The Sustainable Design Group (SDG) thinks strategically about the day-to-day activity of putting buildings together, introducing sustainability ideas to the firm. The SDG intranet site educates the firm's designers, supports the exchange of ideas, and distributes tools and materials for promoting green goals.
NBBJ is using the Leadership in Energy and Environmental Design (LEED) Green Building Rating System, a program of the U.S. Green Building Council (USGBC). LEED enables us to quantify sustainability differences between projects. This holistic system of analysis reaches from the initial planning stages of a project through building commissioning and operation.
It has received widespread support, including a decree by Seattle mayor Paul Schell to achieve a silver rating on all future city projects over 5,000 square feet. NBBJ has been using LEED to measure progress and keep track of goals. Comparisons with past projects make the possibilities for improvement obvious.
Goal tracking begins with a project checklist that differentiates definitely achievable goals from the possibly achievable. It also shows the relationship between the work of consultants and the work of the architects.
Tracking forms are updated after each project phase with a LEED sustainability score. Encouraging innovation and excellence beyond the basic LEED rating is our next step. The USGBC intends to rework its rating system every two years, so they might stay ahead of us.
Projects Using LEED
NBBJ's Seattle Justice Center falls under Mayor Schell's requirements to achieve a silver LEED rating. This is not easy, especially for a high-rise building.
One example of how LEED influenced the design began with the team's desire to set high performance standards for energy efficiency. They wanted the west facade to express a balance between aesthetic, functional, and greening goals. They wanted to maximize glazing for the views and an open expression, so they created a double-envelope curtain wall. A thermal chimney between the glass layers exhausts heat gains at the top and prevents interior heat gains.
The U.S. General Services Administration came to NBBJ for a new Federal Courthouse that would satisfy the strong support for green buildings of regional administrator Jay Pearson. The team uses LEED to track the client's sustainability goals while trying to achieve a silver rating. A DOE 2 analysis computed mechanical system alternatives.
The team chose and tested displacement ventilation for high volume spaces at the south wall and the main lobby. They presented to the client a sustainability report with a range of possibilities. The final rating will not be determined until the project is completed, but constant tracking ensures that goals do not get lost in the last stages of design or construction
The Swedish Cancer Institute is a proposed addition to an existing 12-story medical building in Seattle. The client had not explicitly stated green design as a goal, but the design team was interested in these ideas. However, the budget was extremely tight, meaning that all decisions turned on first cost issues.
The project provides several object lessons. The design team needs to be willing to move away from traditional practices. Consultants need to share in greening goals from the beginning if their innovations are to be incorporated.
Design strategies need to be based on costs, but the first cost can sometimes be allowed to rise when a fast payback is available. Other successes on the project include low-emissivity, double-insulated glass and elimination of volatile organic compounds in paints, adhesives, and casework substrate. A comprehensive construction waste management plan will result in a significant amount of material being recycled, salvaged, or reused.
Pushing the Limits of Sustainability
A final example is the Hall of Still Thought (HoST) in Taichung, Taiwan, a gathering place for the Tzu Chi Buddhists. One of their missions is environmental education. As a metaphor for Buddhist endurance, they challenged us to design the HoST to last 2000 years.
In collaboration with the engineering firm of Ove Arup Partnership, NBBJ has had to rethink modern structural and mechanical systems. As in many of the choices we make when designing high-performance buildings, the higher costs associated with more durable materials become reasonable in light of life cycle costs.
Design considerations include the need for flexibility because the interior might be remodeled fifty times over the course of two millennia. The form of the building also aids in establishing a passive cooling system for the interior. Exhaust stacks and courtyards increase access to air movement and daylight. To maximize ventilation, operable windows have been optimized within the structural and aesthetic framework of the design. They will also increase access to natural light, which will reduce heat gains from electric lighting. These strategies will continue to be refined and expanded as we complete design.
An example of the benefit of early coordination with the engineers is the use of the computational fluid dynamic model that enabled Ove Arup to study how the building would perform in the absence of mechanical cooling. Their conclusions facilitate the design of passive cooling options. This is in contrast to the more traditional method that brings in the mechanical engineers after the design is already well established. That practice tends to oversize equipment and bypass opportunities for engineering innovations.
The Sustainable Design Group has helped to change the way we design buildings at NBBJ. As these ideas become more client-driven, they will play more significantly in the outcome of the designs. Using LEED to bring performance design guidelines into the process has been an effective tool.
As we use it on more projects, more teams will become familiar with concepts essential to thinking about sustainable design. Also, as more clients demand buildings that push the greening envelope, we will be able to take LEED to its limit. Then sustainable design ideas will continue to multiply, and we will be exploring new ideas on how to keep improving the performance of our designs.
Ross A. Leventhal is a designer at NBBJ in Seattle, Washington.