It doesn’t take a genius to figure out why St. Francis Hospital & Health Centers is going to build a new ER and medical office complex near Greenwood: The area has been growing 10 times faster than the city of Indianapolis over the past decade.

The $20 million facility, which St. Francis disclosed its plans for last week, would attempt to capture some of the 32-percent growth in population Greenwood experienced from 2000 to 2009, according to Census Bureau estimates.

“That’s a fast-growing area,” said St. Francis spokesman Joe Stuteville, adding, “We just felt there was a particular need for ER services.”

The free-standing ER, which is projected to open in September 2012, would be the third such facility in the Indianapolis area. St. Vincent Health opened a free-standing ER in Fishers in 2008. And Witham Health Services opened one outside Zionsville in 2009.

Karlsberger, a health care architectural firm in Columbus, Ohio, describes the free-standing ER as a key hospital strategy to increase market share in lucrative suburban communities while establishing a presence in locations that are likely to need a full-service hospital.

For 10 years St. Francis has owned the 50-acre site where the new ER will be built, along Indiana 37 at Fairview Road. It was planning to build a facility there a couple years ago, but the recession and Wall Street meltdown forced it to wait until more favorable financial times.

The new facility is roughly a 10-mile drive away from either St. Francis Hospital in Mooresville or St. Francis Hospital in Indianapolis.

The Indianapolis campus is undergoing an expansion of its emergency room in a project that will be completed by May 2012. St. Francis will be ending emergency and inpatient services at its oldest hospital in Beech Grove once the expansion at the Indianapolis campus is complete.

But in spite of the proximity of St. Francis' existing hopsitals, Greenwood’s growth—roughly equal to what Carmel and Noblesville have experienced this decade—convinced St. Francis that there is an unmet need. Also, larger rivals Clarian Health and Community Health Network have either expanded or explored expanding facilities in Indianapolis' southern suburbs, challenging St. Francis' dominance of the region.

St. Francis expects its new facility to employ as many as about 265 workers—and as many as 400 if it adds a planned second phase. The hospital system will be changing its name to Franciscan Alliance next year.