The Duke Energy Center—owned and operated by Wells Fargo—achieved a number of notable firsts. When completed in 2010, it was the largest and second-tallest building in Charlotte, North Carolina, at 1.5 million square feet and 48 occupied stories. It’s still the only project in North Carolina to have Platinum certification for [LEED] Core & Shell Version 2.0, and it was the first office tower in the world to receive Platinum certification in that rating.
We made the decision early on to pursue LEED certification. We never said we wanted to be Platinum; we just wanted to construct a resource-efficient building that promoted the health, well-being, and productivity of the people who were going to be working in the building. We didn’t know much about LEED though, so we started the journey without a specific target in mind in terms of what level of certification. Somewhere during the second quarter of 2006, a construction manager with our general contractor, Batson-Cook Construction, approached us and asked for some targets, so we went back to the drawing board and developed them. We aimed at our “triple bottom line” of people, planet, and profit by making educated guesses about productivity; energy, water, and waste efficiencies; and return on investment. That really enabled the design and construction team.
There was a challenge almost every step of the way. We had a 23-acre, below-grade parking deck, and it took us a year to just dig the hole. The upside of the duration for this effort was that it gave us the luxury of time to analyze and test strategies and drive decisions based on facts. For example, we had lot of consternation around waterless urinals because we did a pilot test in another building, and the urinals weren’t installed correctly, leading to anecdotal data about how they just don’t work. Since we had time, we did another two pilots and made sure we addressed the installation errors. They were successful, and the waterless urinal conversation became a nonissue.
We had huge success with water efficiency, way beyond our targets. Downtown Charlotte has an abundance of contaminated groundwater. Normally you’d treat that enough to dump it into the storm-water system, but Tempest Environmental installed a water-treatment system that takes 90 percent of our contaminated groundwater and cleans it enough to drink. We use that water for cooling towers, and that alone drives 10 to 15 million gallons of water savings per year. It’s a big part of our total water efficiency. We save approximately 30 million gallons of water per year through a combination of rainwater and condensation collection, groundwater purification, and a 46 percent reduction of domestic water used in bathrooms.
The Duke Energy Center is also 22 percent more energy efficient than a traditionally built tower of comparable size. We save approximately 5 million kilowatt-hours per year, equivalent to the annual energy use of about 450 homes or more than 3,500 metric tons of greenhouse gas emissions each year. We do it through the use of blinds that direct light into the building, lighting controls that respond to the amount of daylight, high-performance glazing on the exterior walls, and highly efficient HVAC systems and controls. All of these things reduce demands on the center’s lighting and cooling systems.
We also require all tenants to pursue LEED for Commercial Interiors certification. We may be the only development in the country to require that. Our fee developer, Childress Klein Properties, was concerned that we would have difficulty leasing the building with that requirement. However, we stayed the course, and today, we’re 98 percent leased. We also sub-meter every floor, and tenants pay for their utilities directly, so they’re incentivized to drive efficiency within their spaces.