Banner Gateway Medical Center 



The completion of Banner Gateway Medical Center provided the growing community of Gilbert, Arizona, with what the NBBJ design team calls the “next-generation hospital.” The phrase aptly describes an advanced facility dedicated to healing and nurturing robust health. Masonry is the prominent feature a user notices when they come upon the building. It’s unique characteristics and placement were important to the development of the project. According to NBBJ partner Mackenzie Skene, “The main objective was providing the community of Gilbert with a facility designed to recall the more hospitable attributes of the Sonoran Desert”. Skene says the design team chose the theme of a desert oasis to imbue the medical center with a resort like tranquility, where patients and their families would find comforting distractions during their time in the hospital. The unique pattern is made up of several different sizes, types, textures and colors of masonry. The horizontal running pattern echoes the shades and textures of the surrounding desert landscape.

To satisfy their aesthetic objectives, Skene says, the designers looked to “regional specific influences” when selecting materials and cosmetic accoutrements to support the oasis motif. The dramatic centerpiece at the entry is a “waterfall” rendered in a fritted-glass curtain wall that appears to emanate three stories above the main lobby. The metaphor is expressed more literally at ground level, where water circulates through a man-made streambed.

More water meanders between the virtual cliffs of the hospital’s diagnostic block and the adjacent patient tower, which are rendered in a variety of materials that mimic the range of texture and color found in the local terrain. The serenity of the outdoor space is exceeded only by the chapel, tucked into a corner of the courtyard, with walls that look as if they float above the ground plane.

This project features a staggering amount of complicated masonry construction including:

  • 145,000 Blocks
  • 45,000 Anchors
  • 13,000 lineal feet (3962 m) of flashing
  • 600 cubic yards (459 cubic meters) of mortar
  • 220 different types of block (based on combinations of color, size, texture, etc)

This project has won multiple awards. It was an Honor Award Winner in the Arizona Masonry Guild Excellence in Masonry Program. The American Institute of Architects, Seattle gave the project an Award of Excellence. “Very well-executed—an oasis in the desert, literally and figuratively,” is how one judge, John Driscoll, an architect and president of the Skokie, Ill.-based AlterCare healthcare real estate company, describes the project. Another panel member, Charles Alexander, principal of the Alexander Design Studio in Ellicott City, Md., notes how the project fits into its location with subtlety and that it’s “not shouting, ‘I’m from the Southwest.’ ”

Thermal Mass
Thermal mass in passive solar design provides two functions: when the sun shines; it stores the solar heat; and it slowly releases the heat to provide warmth after the sun sets. Concrete masonry walls and concrete paver floors are very efficient thermal storage mediums, and are commonly used in passive solar buildings to provide these functions. Masonry location and thickness are important to passive solar design, as are the conduction, specific heat and density. As these three properties increase, the heat storage effectiveness generally increases accordingly. However, very high conductances should be avoided since this can shorten the time lag for heat delivery. One important performance measure of passive solar buildings is the ability to maintain comfortable indoor temperatures. The amplitude of the indoor temperature swing is determined by the amount of effective thermal mass in the building. As the amount of thermal mass increases, the daily indoor temperature swing typically decreases.

Glazing allows solar heat and light into the building. Choice of particular glazing products, sizes and locations will vary with the desired heat gain, cooling load avoidance and day lighting needs. These may vary within the building according to how the interior spaces are used.
For example, because of glare, areas such as lobbies and atria may be more appropriate on a south-facing wall with a large amount of direct sunlight, than, for example, an office space.

Appropriate shading helps prevent solar heat gain during the summer. Shading may include permanent overhangs or porch roofs, moveable awnings, shutters, vegetation to shade east- and west-facing windows, and/or limiting east/west glass.

Venting can rid the building of heat when the thermal mass is saturated. It can also provide outdoor air to cool the building when the outside air is cooler than the building’s thermostat setting, such as by  recooling the building at night. Ventilation can be accomplished using natural ventilation or using an exhaust fan tied to a thermostatic control. CMD