CREJ - Property Management Quarterly - November 2015
The U.S. Government Services Administration recently finished a retrofit on the Byron G. Rogers federal office building in downtown Denver. The project sought to update the building to make it more energy efficient and act as an economic catalyst during the Great Recession using American Recovering and Reinvestment Act funds. GSA is the largest public real estate organization in the nation, acting as owner and manager for the workspaces that house 1.2 million federal workers across the country. For this project, the general contractor was Mortenson Co., the architects were Bennett Wagner & Grody and HOK, the M/E/P engineer was RMH Group Inc., and Rocky Mountain Institute acted as the sustainability consultant. The extensive retrofit of Byron G. Rogers building, located at 1961 Stout St., included a three-pronged sustainability plan – to reduce energy loads, capitalize on energyefficient equipment and incorporate renewable energy, according to a RMI case study on the project. The existing exterior windows were replaced, the building’s lighting was retrofitted with LED, and the interior architectural finishes were removed and replaced. Building systems, including mechanical, electrical and fire life safety, also were replaced. The project reinsulated the exterior walls and used low-flow and infrared fixtures to achieve water savings of 30 percent. Updates to the elevator system using regenerative drive technology reduced the vertical transportation energy by 15 percent, according to the case study. “The improvements are expected to create 55 percent overall energy reduction in the federal building,” said Adam Rankin, GSA building manager. “That means GSA will reduce its greenhouse gas emissions by more than 2,908 tons of carbon dioxide, which is the equivalent of taking 612 cars off the road or providing energy to 266 average-sized homes.” The building, home to 11 federal agencies with more than 900 employees, is expected to attain LEED Gold certification for New Construction and an Energy Star score of 95. The project’s goal is to provide a 50 percent cost savings and targets 39 kBtu per square foot per year as the energy-use intensity based on fully occupied energy model. Over the course of almost five years, 8,300 employees worked on the project. Of the $160 million project budget, $147 million came from ARRA dollars. And more than 40 percent of those contracting dollars, or $59 million of the project’s subcontracting work, went to small, local businesses, Rankin said. The 2009 ARRA, commonly referred to as the stimulus, included funds allocated to create jobs, boost the economy and increase the energy efficiency of federal facilities. The 620,000-sf building originally was completed in 1964 as a federal facility that was occupied by only federal tenants. It is fairly common for federal agency buildings to be at least 50 years old. GSA did periodic surface-level renovations over the years to improve the appearance of certain floors, but updates were considered minor. The ARRA project was the first major renovation to the building. Because of the building’s position, the team had to be creative when considering heating-cooling mechanisms that could take advantage of downtown Denver’s orientation, which is on a suboptimal 45-degree angle off of north south, said the RMI study. This positioning means that one of the building’s façade’s faces northeast and the other southwest, making one side hotter than the other. In order to address this issue in the most efficient way, the building invested in two technologies – a chilled beam system and a thermal storage system. The whole-systems approach uses a heat reclamation and thermal storage system that captures heat from the warm side to heat the cooler side, said the RMI study. There is a 50,000-gallon water storage tank in the basement that stores excess heat during the day for release at night. And the chilled beams transfer temperature from one side of the building to the other. “GSA can store enough to heat the building on a cold winter night without turning on the gas boiler, and even over the weekend,” said Rankin. To incorporate renewable energy, roof-mounted solar thermal panels will offset the building’s energy to heat water. Overall, the anticipated energy-use savings will equate to about $500,000 a year. The project exemplifies GSA’s vision and commitment to the downtown Denver community by preserving and converting an older building into a high-performing, sustainable structure and a first-class space, which will extend the building’s life for another 75-plus years, said Denise Turner Roth, GSA administrator. “The ability to retrofit this building and keep the employees here in the downtown community, which supports the local economy, is something that represents our priorities,” she said.