When Memorial Sloan Kettering Cancer Center, New York City, began plans to build a new cancer surgery center a few years ago in Manhattan, constructing a horizontally oriented ambulatory care facility was out of the question.

With vacant land at a premium, the only way to build was up, so up they went, says Suzen L. Heeley, executive director of design and construction at the cancer center.

Construction is well underway for the new vertical, $280 million, 176,000 sq. ft., 15-floor Josie Robertson Surgery Center that will offer minimally invasive and robot-assisted surgical technology in a patient- and family-friendly environment. The freestanding outpatient and short-stay cancer surgery center is scheduled for completion in January 2016.

While distinctive for its care and design, Josie Robertson is indicative of the rapid growth in ambulatory care facilities offering varying levels of clinical services across the United States.

According to John Wilson, president, HSA PrimeCare, a health care real estate developer in Chicago, the smaller new ambulatory facilities generally start at about 10,000 sq. ft. and may provide urgent care and primary care services at consumer-friendly locations. Multispecialty centers that provide primary care and urgent care offered by a wide range of specialists can range from 70,000 to 150,000 sq. ft. or more, he says.

New York City leads the United States in new ambulatory care space under construction or planned. An estimated 3.3 million sq. ft. to cost $2.2 billion are under construction or are in the late planning stages, according to Revista, a health care real estate data and analytics firm in Annapolis, Md. Of those projects, 75 percent will be built off campus.

There are many reasons for the growth, including changes in reimbursement, says Jeffrey Drucker, vice president, northeast region, Array Architects, New York City. Cost of health care delivery and patient convenience are important drivers, too, he says.

Plus, in a competitive market, all health care systems are using new ambulatory care space to extend their brand.

“People want same-day surgeries for more minor procedures or for procedures that years ago would have required an overnight stay or longer,” Drucker says.

“Today, only 10 percent of all MSK patients will ever have an inpatient encounter whereas, 20 years ago, care was provided predominantly on an inpatient basis,” Heeley says.