When MacArthur, Means and Wells, Architects (MMW) entered into a contract with the Missoula Federal Credit Union (MFCU) for a new branch in central Missoula, the credit union’s board and staff encouraged MMW to design the most environmentally responsible building possible. Further, they wanted a building that embodied MFCU’s commitment to social, environmental and economic improvements. With those goals, MMW set out to design a building that reflected MFCU’s commitment to its members and the community as a whole. “This building is our mission statement come to life,” said Joni Walker, senior vice president of MFCU. “MFCU promotes its members’ financial well-being through our commitment to innovation, education and exceptional service. Because of the innovative, new ideas we implemented in this building, we will be able to reduce our ongoing, long-term operational expenses.

Recognizing that buildings consume a great deal of resources throughout construction and use, products and systems were evaluated and selected that minimized the building’s embodied energy as well as future energy consumption and resource use. Located on a piece of land formerly used by a lumber mill in central Missoula and surrounded by community services and dense residential development, the site enforced the project mission by reducing sprawl to save farm land and shortening commuting distance.

Traditional building products were analyzed for their embodied energy, including travel distance to the project site. The new branch pioneered the use of a ‘concrete’ product that eliminated Portland cement, a product with high embodied energy, from the building. Footings, foundation walls, floor slabs, pre-cast beams, exterior wall panels, and coping, sills and lintels all use a ‘concrete’ mix that utilizes 100 percent fly ash (a waste product of coal-fired power plants) and recycled glass aggregate. Since Missoula does not have a glass-recycling program, the ‘concrete’ is made from regional waste products that may otherwise be sent to the landfill. This is the first known building in the world where all concrete is made of 100 percent recycled content.

Regional materials were prioritized during design to both tie the building to Western Montana and reduce resource use for delivery and maintenance. North Slope Sustainable Wood, a locally sourced sustainably harvested product, was used extensively for wood wall framing. Interior wood, casing, trim, and interior lite framing was sourced from sunken logs exposed during the removal of the Bonner and Milltown dams outside of Missoula. Native and drought-tolerant plant species, which do not require a permanent irrigation system after establishment, were selected around the site perimeter. Adjacent to the building, a greywater collection and distribution system provides water to plant species that are not drought tolerant to our climate. Overall, over 55 percent of the total building materials value is comprised of building materials and/or products that have been extracted, processed and manufactured within 500 miles of the project site. Over 93 percent of on-site generated construction waste was diverted from the landfill, and over 40 percent of the total building materials content, by value, contain recycled materials.

Energy and daylight modeling were used to incorporate resource-efficient measures throughout the building. High R-value structural insulated panels (SIP) were used for the roof and walls, and rainscreen construction was used for exterior cladding resulting in a high-performing envelope with little thermal bridging. Triple-pane high-performing window systems with low U-values and solar heat gain coefficient but high visual light transmittance reduce lighting, heating and air conditioning loads. Over 80 percent of regularly occupied spaces are daylighted with a minimum 2 percent glazing factor, and over 96 percent of regularly occupied spaces have access to views. Occupancy sensors, dimming ballasts, and energy-efficient light fixtures were specified throughout to provide appropriate lighting levels while reducing energy consumption. The HVAC system has demand control ventilation, which closes outside air dampers when spaces are not occupied. Boilers that are efficient at part-load conditions and groundwater cooling were included to minimize energy usage. On-site renewable energy provides almost 13 percent of the building’s energy usage.

The 6,700 square-foot new building, completed in 2008, has been awarded LEED-NC v2.2 Platinum certification. This is the first LEED-NC v2.2 platinum building in Montana. The project has helped spur the interest in functional, innovative green building design in Western Montana. “The technology we are utilizing creates efficiencies in serving our members and the opportunity to educate our members and our community about the ‘green’ aspects of the project allows us to speak to our community in new ways,” Walker said. “We have become the ‘green’ financial institution in our market, and we’re proud to carry that moniker.”