Cashing in on Energy-Sensitive Design
The architectural research firm of Eley Associates developed the contract for the Oakland building, which was designed by Fentress Bradburn Architects, Ltd., of Denver. Charles Eley and his staff modeled the building's energy consumption on a computer at several phases of design and will continue its evaluation through commissioning and the first few years of occupancy.
In a nutshell, performance-based fee contracting rewards architects (and/or builders) for meeting specified energy goals and penalizes them for failing to meet them. The bonus could be a substantial proportion of the design fee. The penalty could be in the form of uncompensated design time or a cash rebate to the owner. Building owners would be willing to offer the bonus because they will pay less in the long run. The gamble will be worthwhile to architects who know how to optimize a building for low energy consumption.
The bonus pays for more time in schematic design, when attention to building form, siting, orientation, and the configurations of glazing and interior walls can have profound effects on daylighting and future energy consumption. If these are ignored, no superficial treatments later in design can make up the difference. The reward system also enables engineers to spend more time on careful analysis, selecting and sizing equipment that will be less expensive and wasteful.
Performance-based fees are easier to implement for energy retrofits. Whether or not a building improves is clearly measurable by comparing utility bills before and after. With new construction, such a comparison is unavailable, so there is a greater reliance on computer modeling.
The buildings included in this experiment are being modeled at several phases. And because the theoretical parameters of occupancy, scheduling, and weather may not match the reality of the building after it's occupied, the model is revised several times during and after commissioning. The building's performance in its second year, compared to a theoretical baseline building, determines whether the design team earns the bonus.
Exactly how that bonus (or penalty) is computed is based on many factors, including the legal structure of the design/construction team. Eley Associates has developed model contract language and computational models for design/builders, construction managers, and owner/architect/contractor triangles. These are described in the manual, "Energy Performance Contracting," available for downloading.
In the case of the Oakland Administration Building, the energy performance target is about 30 percent more stringent than minimum code requirements. Fentress Bradburn complied with a variety of measures including limiting electric lighting to about one watt per square foot and minimizing solar heat gain with small window areas and low-e glazing. Although the final test won't come until after the building has been occupied for a year, it has met the energy goals in every computer simulation so far.
Interestingly, efforts to save energy may create unexpected benefits. For example, a building for Pennsylvania Power & Light's drafting engineers was retrofitted with high-efficiency lamps and ballasts fitted with parabolic louvers. These directed light to specific task areas, reducing glare and veiling reflections, while ambient light levels were lowered. The energy payback was calculated at 24 percent annual return on investment.
Then it was discovered that the more pleasant environment, enhanced by the variation in lighting, also improved employees' productivity. That and fewer sick days increased the actual return to around 1000 percent per year! It would be difficult for an architect to predict such an effect, much less to guarantee it to owners, but isn't that a rosy future to contemplate? When rational fee structuring in all areas—not just energy consumption—truly rewards architects for good design?
B.J. Novitski is managing editor for ArchitectureWeek and author of Rendering Real and Imagined Buildings.
This article first appeared in Architectural Record, February, 1998.