Green Building at Duke University: Potential Energy Savings and GHG Benefits Achieved by Renovating Existing Residence Halls

Abstract

In the U.S., buildings currently account for 65% of total electricity consumption, 36% of total primary energy use, 12% of potable water consumption and 30% of total greenhouse gas emissions. The growing field of green building encourages non-traditional building designs that reduce energy use and natural resource consumption which in turn minimize adverse environmental impacts. This study assesses the energy and environmental benefits achieved through a recent LEED-certified renovation at Duke University’s Kilgo Quad. Data for this analysis was collected by performing sustainability audits and reviewing utility records to quantify changes in energy and water consumption at Kilgo Quad and Few Quad, a similar building which is slated for renovation in Summer 2008. Compared to the 2001 baseline, Kilgo Quad experienced significant reductions of 20% in electricity consumption and 35% in water consumption immediately following the renovation in 2004. However, Few Quad experienced greater reductions of 35% in electricity consumption and nearly 50% in water consumption over the same time period, without the benefit of any renovation. After 2005, annual increases in resource consumption were two to three times larger in magnitude at Kilgo, returning the building to nearly pre-renovation levels by 2006. By 2006, despite having less square footage, fewer people and the benefit of the recently-completed renovation, Kilgo Quad used more energy per square foot and more water per person than Few Quad. Kilgo Quad’s overall CO2-eq emissions actually surpassed the emissions from Few Quad in 2006 as well. While no single factor can be determined to account for this under-performance, it is my belief that changes in individual demand for resources were a key driver behind the unexpectedly high consumption levels at Kilgo. Upgrades to electrical wiring increased plug-in load capacity by a factor of ten, enabling occupants to use electricity differently and possibly contributing to greater phantom load impacts and a rebound effect, neutralizing any efficiency gains expected after the renovation. Further study is needed to determine exactly why Kilgo Quad is not performing as well as Few Quad and exerting a larger impact on the environment. Green building offers numerous benefits, and can contribute significantly to Duke University’s goal of becoming carbon-neutral in the future, however it should be noted that achieving LEED certification does not necessarily guarantee long-term reductions in energy and water consumption. University planners must consider whether a renovation will change a building’s capacity for consuming resources and then seek a good balance between optimal comfort and effective resource management. Occupant education and improved metering strategies are also critical keys to successful green renovations at Duke University.