A group of designers and specialists was recently assembled by the Rocky Mountain Institute's (RMI) Green Development Team, a non-profit "think tank" in Aspen, CO, specializing in sustainable design. Alexis Karolides, the RMI facilitator, had invited daylighting and electric lighting designers, a mechanical and electrical engineer, a landscape architect, a water quality expert and an energy efficiency expert from across the country to meet with members of the client group to develop sustainable building design concepts for a new facility. On the client's side were representatives from facilities, engineering, design, management and human resources. Twenty-two people in all were brought together to take part in a one-day intensive design "charrette." These intensive design workshops are becoming more prevalent throughout the design and construction industry, and are especially important in sustainable design circles, where synergistic relationships in design and construction can be critical to the success of a project.

A building design charrette is typically a two-to-four day meeting where design professionals, client groups, public officials and even community leaders and citizens can work together to move specific projects closer to social and environmental sustainability. Our one-day charrette was assembled to discuss a broad range of sustainable design and education concepts before a specific building project was addressed, almost a "charrette primer." The client had more than one building site as an option for new construction and had renovations of other sites to consider. The issues presented in this first workshop were meant to influence the site selection process and the early schematic design of the facility. The goal was to look at the full potential of a building and its impact before any substantial design work had been performed. Once the client has digested the results of our daylong exercise and applied them to a specific building on the selected site, the team will reassemble for a two-to-three day building design workshop that is more detailed and in-depth.

The Charrette Process

The traditional design process can offer little opportunity for true design coordination or innovation. In today's design and construction climate, project schedules seem more compressed than ever. Schematic Design and Design Development are sometimes combined into a single design phase to save time. Different team members can work in isolation, with consultants becoming involved after many important design criteria have been set. Mechanical, electrical, lighting and fire protection specialists fight for space in the same oversized and overstuffed ceiling plenum. With tight schedules and limited budgets, there is little incentive to spend additional time on coordination.

The charrette process has been around for quite a few years, and groups like the American Institute of Architects Committee on the Environment have studied, developed and promoted techniques that have led to a better understanding of how to organize such a workshop. Charrettes are gaining popularity because they are helping make better buildings, and they can provide an opportunity for a more satisfying design experience.

The most successful charrettes are interactive and integrated. Using techniques that might best be described as "group brainstorming," these workshops can promote discussions that move beyond conventional thinking by building on ideas from many different participants. Complex environmental and building design issues are more easily dissected and understood in a diverse forum. Design concepts can reach a high degree of resolution, and the additional coordination time up-front can save time in other phases of design.

For example, "on site" water management and treatment of local wastewater were particularly important design issues for one of the sites being considered. True to the charrette process, the wastewater and runoff were examined for their opportunities, and several possibilities emerged for on-site use, reuse and treatment. Some of the potential solutions brought up for future study, such as an interior and exterior fountain or water wall features, began to influence building design and orientation. Building orientation, which is linked to many other issues, can be critical to the success of a project because of the different daylighting and mechanical design opportunities that some exposures provide.

The exterior lighting was also a topic of discussion. Some members of the client group who were involved with the marketing and corporate image departments had recently talked with citizens concerned about light pollution and light trespass. Most people think of light pollution as the wasted and unwanted light that causes a "sky-glow," while light trespass is often equated with "the light shining in my window." We talked about what types of lighting equipment were appropriate for the project and why a white source allowed for better visibility in low light environments. There was also a discussion about appropriate light levels and why the uniformity of light can be more important than the amount of light. Many of the different design possibilities will clearly influence the final site selection.

Organizing a Charrette

Although there is no ideal way to organize a charrette, there are some common techniques that seem to promote success. For example, our Fort Worth charrette began with a dinner the night before. In a more relaxed atmosphere, we were able to get to know the client and begin to understand some of the culture, issues and challenges surrounding their business. But perhaps even more importantly, the client group got to know the design team. Building a little bit of trust and understanding went a long way during the next day's design meetings. I sat with members of the client group, including individuals from the facilities, engineering and human resources.

The charrette day started off with brief presentations by members of the design team. This short series of "show and tell" sessions introduced many of the sustainable design concepts that were used to guide the design throughout the day. Examples of successful projects were presented, and the client group responded with discussions pertaining to the design and operation of their proposed building. As is usually the case, members of the client's engineering and facilities team were particularly vocal and provided information about specific building performance and operation that was critical to the design process. Groups were then formed to work on developing goals and strategies for different parts of the building and site, such as landscape and water, building form and envelope, and mechanical, electrical, and processing. Different individuals with complementary skills were assigned to each group, but cross-pollination and movement between groups was encouraged. Each group met separately and developed materials, and then all the groups reconvened to share ideas, discuss issues and develop integrated strategies. This process continued throughout the afternoon. Not surprisingly, some very good ideas came from members of the client group.

Avoiding the 'Easy Route'

A great deal of discipline is necessary to resist forming quick opinions and "cherry-picking" the easy cost or energy saving ideas. Far greater energy savings and quality increases are often possible when all the issues are analyzed simultaneously. Measures that do not seem to make sense initially can play a critical role in an overall strategy. When assessing design and cost considerations, it is very important to use a holistic approach that allows for individual strategies to have multiple benefits, and for the cost trade-offs to be analyzed in such a way that those credits and added costs are accurately accounted. In other words, the added costs for better windows and daylighting strategies may be offset by reductions in the electric lighting load and mechanical equipment. The result can be a building that has a better quality visual environment, saves energy and is easier to maintain.

For example, lighting is an area where easy cost and energy savings are often identified, but even larger savings are often possible when a more holistic approach is pursued. In our building design group, we examined the client's current lighting practices and discovered that the standard in their existing warehouse environments was to use high intensity discharge (metal halide) high bay lighting. The visibility in these environments is compromised because of the poor uniformity of light and the excessive brightness and glare of the metal halide luminaires. We found that by using the new high output T5 fluorescent lighting in the warehouses, we could improve visibility, reduce energy use and extend the maintenance schedule with the longer life lamps.

This is just what any client wants to hear, but rather than writing down this idea and moving on, we pushed the concept further. What the building group really wanted was daylight in the warehouse so that we would not need electric lighting for most of the day. In our movement between other groups, we discovered that other designers were very receptive to the idea of a clerestory near the warehouse area because it helped them solve some of their own issues. For example, the client's engineer thought that a change in roof height would work well because warehouses of different heights were needed for programmatic reasons. A tall clerestory wall with access to daylight also worked with the notion of an interior water feature. With a daylit warehouse, the proposed fluorescent electric lighting system could be turned off during the daytime. The total number of luminaires could be reduced because lower light levels are required at night, and with the instant start capabilities of the fluorescent system, occupancy sensors could be used for additional control of the night illumination.

By "pushing the envelope," savings in equipment, energy and maintenance could be much larger than simply changing from metal halide to high output T5 fluorescent lighting, and the quality of the daylit environment would be higher during the busiest work periods.

Secrets to Success

What needs to happen to make a charrette successful, and how does a client get the most out of a charrette team? Architect Robert Berkebile, FAIA, principal of BNIM Architects in Kansas City and one of the founding members of the American Institute of Architects Committee on the Environment, insists that three issues are critical to the success of a workshop. First, a concerted effort must be made toward teambuilding before the charrette begins. The greater the spirit of collaboration, the better the results are likely to be.

Second, all the participants assembled for the charrette need to either be very well informed about the goals of the exercise, or come with knowledge and be willing to grow and work in a collaborative fashion. The client needs to provide participants who are as committed to the process as possible. One bad apple may not spoil the entire workshop, but it can certainly leave a bad taste in your mouth. Establishing specific goals is crucial, and the client needs to play a major role in the setting of goals. You cannot measure success or failure without some goal to evaluate against.

Finally, the intelligence, experience and diversity of the entire team, client and design groups are real factors in getting the most out of a charrette. As Berkebile says, "It can be the difference between pushing the envelope and actually changing the 'state of the art'."

Our Fort Worth charrette concluded with a summary and comments on the day's work. The group had started the night before not knowing where the workshop might lead. In one day we had not completely designed the building, but we had addressed many specific issues, such as what type of light source or building material might be best for a given situation. However, we had also focused on much more difficult ethical questions surrounding environmental responsibility. There was a consensus that through the greater awareness and environmental thinking during the workshop, the new building would be a better and more productive environment.