The city of El Paso, Texas, has been worthy of attention over the years for a number of reasons, in particular because of its continued status as one of the safest large cities in the United States—a surprising distinction since unemployment is high, poverty persists, and adjacent Ciudad Juárez, Mexico, has only recently begun to shake its bad reputation as a narcotics trade capital. The border town has a vibrant history as a continental crossroads, but it has never been singled out for a commitment to sustainable building. That has changed with the completion of Paisano Green Community, a low-income public senior-housing project that is targeting net zero energy use and LEED Platinum certification.
Location El Paso, Texas (Rio Grande watershed)
Gross area 182,952 ft2 (16,996 m2)
Cost $14.8 million
Date completed August 2012
Annual purchased energy use (based on simulation) 5.8 kBtu/ft2 (66 MJ/m2), 87% reduction from base case
Annual carbon footprint (predicted) 2.2 lb CO2/ft2(10.7 kg CO2/m2)
Program Senior housing, community center, gardens
TEAM & SOURCES
Windows/doors Pella Impervia (fiberglass)
Interior doors Masonite Flush Door Series (hollow core)
Roofing GAF EverGuard TPO 60 mil
The project was commissioned by the Housing Authority of the City of El Paso (HACEP) and designed by Boulder, Colorado–based Workshop8. This melding of vision and opportunity came about when federal stimulus-package funds were made available to housing authorities across the country in 2009. An $8.3 million grant from the American Recovery and Reinvestment Act (ARRA) was the bait, and Gerald Cichon, HACEP's CEO, had the vision. "Our mission has always been safe, clean, affordable housing," he says, "but I saw this grant as a chance to do something great—to make a statement and put El Paso on the map for sustainability." With the help of two University of Texas professors, Cichon put out a request for proposals with extensive requirements, citing housing projects he appreciated, including some by firms like Mexico's TEN Arquitectos and the Netherlands' UNStudio. "I like modern," says Cichon. Workshop8 won the commission, and the race to complete the project on a very tight schedule dictated by ARRA commenced.
Ninety-three seniors over the age of 62 applied and were granted the opportunity to live in the 59,800-square-foot community based on their exemplary track records at previous housing projects and willingness to comply with the energy-saving lifestyle needed to achieve their new home's net zero status. The project was completed on a 4.2-acre site, once a smaller derelict housing project surrounded by commercial entities.
Paisano stands on its own as a modern, elegant community that fits its climate and site. The central garden is flanked by four three-story "flats" buildings to the west and the linear two-story community center to the east. A canopy wall connects the flats, protecting the west facade from harsh afternoon sun, winter wind, and noise. It also provides a large area for photovoltaic (PV) panels on its upper set of beams; the project has a 165-kilowatt solar array, distributed atop most of the flat roof surfaces.
"El Paso is known as the Sun City, because it gets 302 days of perpetual bright sun each year," says Workshop8 principal JV DeSousa. But it takes more than solar bling to bring a project of this kind to net zero. It was originally planned to be modular, but prefabrication was scrapped to achieve high-efficiency, tight building-envelope construction, with R-26 walls containing a hybridized system of insulation with minimal thermal bridging. Recycled, recyclable, low-maintenance, or local materials were used throughout.
When it came to outdoor sustainability, some LEED mandates had to give. "One size does not fit all," says DeSousa about one LEED Platinum credit for shading that just wouldn't work for this climate. "The requirement calls for shading of hardscape areas, which is usually accomplished with trees," says Aaron Nelson, LEED consultant and sustainability coordinator for the project. "For this project it just wouldn't be sustainable in the dry, hot climate to have that many trees to water." The team went to the U.S. Green Building Council to plead their case, and the USGBC agreed to change the requirement for this specific project. Splurges on such high-end systems as heat-pump water heaters, which are four times more costly than electric water heaters, were made with long-term efficiency in mind—a perspective that extended to energy-recovery ventilator units, high-efficiency fixtures and appliances, ultralow-flow plumbing fixtures, and LED lighting.
Once the systems were in place, the education began. According to Nelson, without the stewardship of the residents, the maximum capacity of the systems could not be realized. Working with HACEP, he developed training programs and incentives to keep residents involved. On a tour of the property with Sergio Cueto, the resident association's president, it's obvious that residents are gratified with the reputation of their home and recognize their role. At midday, Cueto's blinds are drawn to keep out the harsh sun, and he proudly shows off a log revealing the numbers he records each month from the energy submeter in his unit. "We're part of the future here," he says. The energy simulation projects a slight shortfall in renewable energy needed to achieve net zero, but without knowing how residents would behave, the team chose not to spend extra money up front, so they undersized the PV array and will monitor it for two years. Room has been reserved for additional panels if necessary.
Teaching residents about net zero energy wasn't the only education that had to happen. According to Mark Bloomfield, energy consultant for the project, finding a contractor and subcontractors was a challenge. "El Paso just isn't used to building these types of structures," he says. Another hurdle was that the publicly held utility company had recently eliminated its net meter rate—anyone who had energy going back into the grid was paid approximately four cents per kilowatt hour (kWh), but when they used energy they would pay 13 cents per kWh. "With the current system in place we would never truly have a net zero project," says DeSousa. Luckily, the company realized it was in its best interest to help Paisano Green, and DeSousa worked closely with it to enable legislation that allows for a very specific entity—almost exactly Paisano Green—to have a net meter rate. "I don't blame the utility company [for not opening this option to more projects]," says DeSousa. "They have to be very careful with these types of things, to make sure distribution of energy is as stable as it can be. It's like trying to hook a small utility company into a large utility company."
Policies, laws, and lifestyles changed with this project, as well as the lives of the design team. Workshop8 now has several housing projects in its portfolio, and continues to refine the building type. While the real results won't be measurable until more than a full year of occupation has passed—in early 2014—interested architects and city housing authorities continue to visit, in hopes that they too can have a similar project in their cities. "I think we've changed the way people look at public housing," says Cichon. "It's our jewel."