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Navajo FlexCrete builds homes, economy for tribe

Navajo architecture students built the first house using Navajo Flexcrete blocks. Traditional features like this courtyard act with the block's insulating properties to keep out the desert heat. (Photo by Navajo Housing Authority)

The Navajo Nation is redefining efficiency—getting a job done with the minimal amount of work and materials—as getting many jobs done with one material: a Flex-crete block from Navajo FlexCrete.

The Navajo Housing Authority isn’t just using the lightweight, inexpensive, "green" building material to build affordable and energy-efficient homes across the reservation. Flexcrete is also a building block in the Navajo Nation's economic development, and in partnerships with Arizona State University, Washington State National Guard and the Santo Domingo Pueblo. If that wasn't enough, the plant is also making a useful product out of 300,000 tons of fly ash annually destined for the landfill.

Powerplant waste becomes business opportunity

Headwaters, Inc., Flexcrete’s parent company, first approached the Navajo Nation Division of Economic Development several years ago with what seemed like just another business proposal. The plan called for using fly ash from Salt River Project’s Navajo Generating Station to manufacture an aerated concrete product. The company proposed building a plant in Page, Ariz., just three miles from Navajo Station. 

Fly ash makes up 60 to 70 percent of Flexcrete's content. “Up to that point, Salt River was disposing of the waste in its own landfill,” said Rick Abasta, NHA public information officer.

Unlike traditional autoclaved aerated concrete, Flexcrete is cured at lower temperatures, so its production requires less energy. Locating the plant close to the source of Flexcrete's main component improves the material's "green" profile from a lifecycle standpoint.

Abasta recalled that then-Nation President Kelsey Begaye invited the housing authority to sit in on discussions with Headwaters from the beginning. The project initially seemed like a good way to support the NHA's mission of providing affordable housing on the reservation. However, as the NHA learned more about Flexcrete technology, "The concept of green building really appealed to us," said Abasta. "We realized that a Navajo-owned factory could cut down the cost of standard stick construction and be an investment in the Nation's future."

Over four years, the proposal morphed into a major venture in which the NHA owns a 10-percent stake in the technology and financed construction of the plant. The NHA bought 10 acres in Page and built the plant, financing the project with a private loan. Opened in 2005, the plant currently provides 14 jobs for tribe members. In the land-rich, but job-poor area, Navajo FlexCrete expects to eventually employ 50 to 60 full-time workers. The additional employees will be added as the company develops the commercial market in Phoenix, Las Vegas and Salt Lake City.  

Navajo students build first Flexcrete home

Marketing opportunities notwithstanding, meeting the tribe's housing needs is the NHA's top priority. So far, the housing authority has built 13 homes on the reservation using Flexcrete from its own plant.

The first was a demonstration home for Mary and Kee Augustine, who had been on a waiting list for a new house for some time. Shortly after the opening of the Flexcrete factory, a group of Navajo architecture students asked to rebuild the elder couple's home for a project. One of the students, Christopher Billey, enlisted his employer, ASU's Stardust Center for Affordable Housing and Family to sponsor the project.

Navajo Flexcrete and the Stardust Center donated most of the materials, and the students designed and built the house modeled on the traditional hooghan. "That house was our 'guinea pig,' and the students made changes throughout the process," said Abasta. "The finished home is 80 percent more energy-efficient than a conventional house." 

The energy-saving properties of Flexcrete contributed to that accomplishment. The tiny air pockets that make the material so much lighter than concrete give the 12-inch blocks used for the Augustine house an insulation value of R35. Originally, the Stardust Center planned to use straw bales until it was discovered that Flexcrete made 12-inch blocks. Straw bales are good insulators, but the heavier mass of Flexcrete is better protection against the high desert climate.

Other measures that add to the home's efficiency include passive solar heating, a traditional shade arbor for natural cooling and a roof that collects rainwater. The water is stored in a 1,200-gallon underground tank with a hand-pump for watering plants and animals.

A number of sensors were also built into the house so the Stardust Center could collect data on its performance. The data will be matched up to projections from the center's computer model. NHA will use the data for marketing Flexcrete, Abasta said.

Others discover Flexcrete

The next Flexcrete construction project was a model housing development for low-income families near Crownpoint, N.M. "Those had the standard NHA floor plans," said Abasta. "Families can choose a three-, four- or five-bedroom home."

The NHA got help on construction from Seattle's 803rd Engineer Detachment. Guardsmen were in the area for Innovative Readiness Training, an annual program that offers engineers unusual training opportunities. In this case, it was the chance to learn how to build with Flexcrete.

Representatives from the Santo Domingo Pueblo visited the construction site of the next NHA housing development in Burnside, Ariz. They had heard about Flexcrete and wanted to know if the material would meet the pueblo's specific housing needs. "The pueblo is very old and new homes have to maintain the cultural aesthetic," explained Abasta. "They needed to know if Flexcrete could support the traditional adobe finish."

The tour answered those questions, and the Santo Domingo Pueblo ordered 10 houses worth of Flexcrete blocks. Abasta said that the development was recently completed.

The list of Flexcrete projects keeps growing. Construction is close to finished on a new NHA development of 20 houses in Low Mountain, Ariz. The first custom home to be privately built with Flexcrete blocks went on the market in July in Sedona, Ariz. The developer advertised it as the "greenest" home in the state. 

Like the word efficient, green as applied to Flexcrete has many meanings. It means the building material was created with a low-energy process using recycled waste from a source close to the plant. It means homes built with Flexcrete need less energy for heating and cooling. For the Navajo Nation, "green" is a growing Navajo-owned business that promises affordable housing and economic growth.