The CH2M Hill corporate headquarters in Englewood, Colorado achieves two separate building objectives that are not always compatible; efficient, cost-effective construction and optimal energy performance. CH2M Hill is a leading engineering firm known for its commitment to the environment. In 2003, it was named “Company of the Year” by the Southeast Business Partnership for outstanding community and environmental stewardship. When CH2M Hill set out to build a new three-building campus that reflected its conservationist tradition, it chose precast concrete wall systems to ease installation, limit construction budgets and create an energy efficient thermal envelope for each structure.

The use of precast also allowed CH2M Hill to leverage additional benefits of concrete construction, including the use of recycled content and locally sourced materials. As a result of the campus’ clever design and the integration of concrete with other ecologically safe building applications, the CH2M Hill headquarters received LEED certification in 2004 from the United States Green Building Council. Today it is one of the most widely known green buildings in Colorado.

Building Efficient with Precast Concrete
Construction with precast concrete wall systems improves efficiency in the construction process, in building utilization and in building maintenance. Precast wall panels arrive at the construction site fully formed, therefore, no concrete is poured onsite, limiting construction time, and significantly minimizing waste.

With time being a valuable commodity in the construction industry, using precast wall systems also minimized costs. Precast concrete expedites the construction process, decreasing the number of labor hours and required to complete a project. Fewer hours of labor translate to a reduction in the overall costs to complete a project. “In Denver, precast is used extensively for two reasons: cost and schedule,” says Paul Todd, formerly of Barber Architecture, the design firm that conceived and executed the design of the CH2M Hill campus.

In addition to avoiding construction delays, cost overruns and construction waste relative to other building systems, the precast concrete wall systems at CH2M Hill’s headquarters provide the same superior energy performance as other insulated concrete structures. Structures built with concrete benefit from high thermal mass and low infiltration. Compared with wood and steel, concrete structures moderate daily temperature fluctuations. Consequently, heating, ventilating and air-conditioning in concrete structures can be designed with smaller-capacity equipment, saving money and resources. And like all concrete wall systems, the precast walls at CH2M Hill are durable and will help extend the life of the building, requiring little maintenance over time.

Recycled Materials
CH2M Hill also demonstrates that cement-based products can create solid, energy efficient walls while incorporating recycled materials to conserve precious natural resources. Cement can be produced by incorporating recycled industrial byproducts into the portland cement manufacturing process to minimize dependence on virgin raw materials. The precast wall systems that support CH2M Hill used a concrete mix that incorporates fly ash, a recovered byproduct of coal burning power plants. Each building on the campus will have the same superior energy performance as concrete structures built with a virgin mix, but will reduce the overall impact on the environment.

Locally Sourced
Another benefit of concrete construction that contributed to LEED certification of the CH2M Hill campus was the use of locally sourced materials. The manufacturing process of portland cement, the binding element of concrete and one of the key ingredients of precast concrete, is not tied to a certain region of the country and the materials involved in the process are readily available all over North America. By using precast concrete, CH2M Hill had the ability to ship more construction materials from the greater Denver area, minimizing transportation costs, energy consumption, and emissions. According to the Precast/Prestressed Concrete Institute, “Fifty-nine percent of the project’s materials were produced locally, nearly three times the 20 percent required in the credits (for LEED certification in this category). The structural and architectural precast concrete components accounted for 39 percent of the materials used to calculate this total.”

Concrete Makes it Possible
The CH2M Hill campus in Englewood, Colorado exemplifies just some of the many cement-based solutions for sustainable development. The use of precast concrete expedited construction and provides a solid, airtight thermal envelope for each of the three buildings. By choosing concrete CH2M Hill was also able to earn LEED points from the USGBC for recycled content and locally sourced materials. The CH2M Hill campus demonstrates that with concrete thinking, buildings that are efficient to construct can also be efficient to operate.

At the 2006 Greenbuild Show and Expo, the United States Green Building Council (USGBC) will lead tours of the CH2M Hill campus to showcase its sustainable features – including a number of benefits from concrete construction that make this one of the top green buildings in Colorado.

Project Summary:
Architect – Michael Barber, Barber Architecture, Denver, Colorado

Precast concrete contractor – Rocky Mountain Prestress, Denver, Colorado

Design engineer – SA Miro, Denver, Colorado

Source:
PCINE Innovations, Spring 2005

US Department of Energy, Energy Efficiency and Renewable Energy: “CH2M HILL Denver Campus, LEEDTM-certifying a ‘Spec’ Building”, Andrea Ramage, CH2M HILL, Bob Kirkendall, IDC Architects/CH2M HILL, Tim Chiddix, Swanson Rink