December 22, 2009 | GBI Insight Home
County of El Paso Makes Sustainability a Priority in Ysleta Annex,
Achieves Three Green Globes®When the County of El Paso set out to build its new Ysleta Annex, one of the primary goals was that it be designed and constructed based on sustainable, energy-efficient and environmentally responsible principles. “We approached this objective in a variety of ways,” said project architect Frédéric Dalbin of Wright & Dalbin Architects. “From the outset, the design included a strong focus on energy and water efficiency, environmentally-friendly materials and indoor air quality—which together enabled us to achieve an ENERGY STAR® rating as well as a certified rating of Three Green Globes.”
Designed to provide a traditional Southwestern plaza feel, the 30,000-square-foot, one‐story Annex includes two stand-alone buildings around an open space comprised of parking, a landscaped area and a small plaza. The buildings house nine county departments, each of which has separate public access from the exterior, and the design includes provisions for a third structure or series of smaller structures should expansion be required.
According to Dalbin, energy efficiency was a key consideration in determining the building’s orientation and volume as well as the positioning and size of windows. Other energy features include awnings for the protection of building openings, strategies to maximize natural daylighting, a high efficiency HVAC system based on hourly analysis, a building automation system, cool roof, and high-efficiency lighting and controls.
In terms of thermal protection, the exterior envelope includes R-30 (4-inch) polyisocianurate rigid insulation on the roof, exterior CMU walls with perlite insulation, R-11 batt inside metal furring stud and 1 ½-inch EIFS exterior finish for a total R-22 value. All windows and storefront are low-e 1-inch insulated glass with thermal break frames.
“In the first three months of use, the two Annex buildings were projected to save 1,200,309 kBtus and 100 metric tons of carbon annually, compared to an average building with an EPA rating of 50,” said Dalbin. “This meets our original ENERGY STAR goals.”
Water is also at a premium in the Southwest, and the Annex includes a number of features designed to make the most of the resource. In addition to drought-tolerant landscaping and low-flow irrigation, the configuration of the buildings provides storm water harvesting for a centralized landscaped space along with other, smaller areas that include natural vegetation and water retention basins. The buildings also feature high-efficiency equipment such as low-flow faucets and waterless urinals.
To achieve its Green Globes rating, the team led by Dalbin completed the online Green Globes for New Construction assessment protocol during the design process. This provided an initial calculation of points the project was likely to achieve, as well as a report noting opportunities for improvement. As part of GBI’s Stage I review process, an authorized third‐party building science expert was then engaged to review the construction documents as well as the energy and daylighting modeling reports. Once construction was complete, this was followed by the Stage II review which included an on-site visit and additional documentation review—after which the third-party assessor adjusted and/or confirmed the percentage of points achieved. Based on this final rating, the County of El Paso Ysleta Annex achieved Three Green Globes out of a possible rating of four.
Established in 1986, Wright & Dalbin Architects, Inc. strives to promote and incorporate the concept of ‘sustainable and green architecture’ into its building designs and renovations. W&DA produces ‘high performance buildings’ and understands that the life and optimum use of any facility depends on sustainable site planning and development, efficient water and energy use, conservation of materials and resources as well as indoor environmental quality.
