High Performing Buildings - Winter 2011 - (Page 61)

e P A R e g i o n 8 H e A d q u A R t e R S Situated on the high plains at the base of the Rocky Mountains, Denver has a semi-arid climate with sunny days and low humidity — ideal conditions for passive building strategies. The Region 8 EPA Headquarters harnesses nature’s resources, capturing the benefits of free cooling, daylighting and solar energy. he EPA Region 8 Headquarters serves the mountain states of Colorado, Montana, North Dakota, South Dakota, Utah and Wyoming. The facility, which opened in 2007, consolidated EPA offices that were previously spread out over 23 floors in two towers. Its setting in the revitalized urban district known as LoDo near alternative forms of transportation serves to remind the public of the EPA’s mission of sustainability. The General Services Administration (GSA) leases the building on behalf of the EPA. Both organizations require LEED Silver for their buildings as a minimum standard. The Region 8 Headquarters achieved LEED-NC Gold using holistic and integrated design, smart site orientation, an efficient underfloor air-distribution system, and a vegetated roof that manages storm water and minimizes the heat island effect. T Minimizing loads The building team designed the massing and orientation to capture the maximum climatic benefits Opposite A central atrium provides daylight to the interior of the EPA Region 8 Headquarters in Denver. Energy modeling showed that the atrium design offered the best combination of energy efficiency and daylighting. (such as daylight and renewable energy) while minimizing thermal loads on the building. The team selected a “double L” design concept (see diagram, Page 62), which satisfied the desire to create a central atrium and worked well with the building’s position on a street grid that is oriented 45° to the cardinal compass points. A “sunward L” with legs facing southeast and southwest receives most of the solar radiation while the “windward L” bears the brunt of most of the wind. A series of preliminary studies comparing the merits of different building massing options with resulting thermal loads and daylight availability confirmed the performance benefits of this “double L” atrium approach. The eastern break between these two wings forms the primary entrance to the building and is adjacent to an urban park, while the western gap orients occupants toward views of the Rocky Mountains. Curtainwall systems for each “L” are designed as siblings, with the south-facing leg tailored to harvest direct sunlight while minimizing solar gain via a series of horizontal sunshades and lightshelves. The other leg is designed to maximize daylight harvesting from the diffuse Winter 2011 HigH north sky while blocking low-angle summer sun with vertical blinds. The nine-story northern leg shelters a roof terrace on the eight-story southern leg from the wind while leaving it exposed to the sun. The building team evaluated the performance of alternative glazing, external shading devices and reflective versus vegetated roof. The team performed these analyses in an effort to achieve the requisite B u i l d i n g At A g l A n C e name ePA region 8 Headquarters location denver owner opus northwest Principal uses office, Conference Center, retail employees/occupants 775 ePA personnel/900 occupants occupancy 100% rentable square footage 300,000 total; 248,849 (ePA) Conditioned space 257,400 Total Cost $90,000,000 Cost Per square foot $300 substantial Completion/occupancy January 2007 distinctions/Awards evergreen Award for ecommercial category, ecostructure magazine (2009); American Architecture Award (2008); federal energy saver showcase Award (2007); leed-nC gold Performing Buildings 61

Table of Contents for the Digital Edition of High Performing Buildings - Winter 2011

High Performing Buildings - Winter 2011
Commentary
Contents
Portland State's Shattuck Hall
Oberlin College's Adam Joseph Lewis Center
Dell Children's Medical Center
CMTA Office Building
EPA Region 8 Headquarters
Honda's East Liberty, Marysville Auto Plants
Advertisers Index

High Performing Buildings - Winter 2011