As one worship service was letting out at Orchard Hill Church in the Cultural District late on a Sunday morning, another was just ramping up about a mile away at Amplify Church in the Strip District.

Each featured high-energy, guitar-led worship with lyrics projected on screens, and each was using a rented space originally designed for entertainment.

And there was another similarity: The worshipers were many miles from their mother churches, occupying very different spaces from the large suburban buildings with ample parking.

The Franklin Park-based Orchard Hill Church rents the theater and other space at the August Wilson Center Downtown on Sundays, while the Plum-based Amplify Church uses a former nightclub on Smallman Street.

They’re hardly alone in what’s becoming an accelerating trend. Nearly two-thirds of America’s largest churches now call more than one address home, according to a recent survey.

“More congregations are opting not to build bigger buildings but to do multisite,” said one of the researchers, Scott Thumma, at the Hartford Institute for Religion Research in Connecticut.

Some of the reasons are practical.

So-called megachurches — typically defined as those drawing 2,000 or more per week — soared into prominence in the late 20th century as a primary engine of evangelical church growth. They are often marked by ever-larger worship centers with theater seating, guitar-and-drums worship music and video-enhanced sermons delivered by a prominent preacher.

In some cases, megachurches’ multipurpose campuses have functioned somewhat like the malls they resemble, where over the course of a week someone could get a sermon, a latte, a workout and a counseling session all under the same big roof.

But churches can build only so big before they reach limits in affordable land, building costs and the number of people they can reach within a reasonable driving distance. With multiple campuses, a church “can maintain a smaller physical size, grow larger and ... grow faster than single-site megachurches,” said the report by Mr. Thumma and Warren Bird of Leadership Network, a church-growth consultant.

Sixty-two percent of the largest churches surveyed have multiple campuses, up from 27 percent in 2005, according to the report, “Recent Shifts in America’s Largest Protestant Churches.” The average large church had 3.5 campuses.

The trend has cultural and not just practical reasons, with churches realizing that even a worship center seemingly designed to reach anybody doesn’t actually reach everybody. Some people don’t have a car to take advantage of the parking spaces, and some prefer something smaller or more rooted in an urban, rural or other cultural context.

In that sense, the multisite trend resembles its close cousin, the church-planting movement — which draws on traditional missionary strategies by trying to bridge cultural divides with local populations not being reached by existing churches.

Campuses such as Orchard Hill’s and Amplify’s, for example, have more of an urban vibe than their suburban mother churches, tying in with local arts and community-service projects.

“We just believe in the city,” said Joel Haldeman, pastor of Orchard Hill’s Cultural District campus. “We believe the city is the center of culture, and we want to be able to do good in our city.” The church, he said, draws everyone from suburban executives to homeless persons coming in off the street.

“It’s a missional feeling for me,” added member Rob King of Ross. He and his wife, JoAnn, work in the city and cite such recent activities as taking part in a recent street cleanup day. “We’re really intentional about making Pittsburgh beautiful,” said JoAnn King.

North Way Christian Community holds 11 services each weekend at its main North Hills site in Pine and others in Oakland, the East End, Dormont and Sewickley Valley. The Bible Chapel has three sites in addition to its main South Hills location. Allison Park Church has its main campus in Hampton plus two others. Crossroads Church, a United Methodist congregation with its hub in North Fayette, has launched four more sites ranging from East Liberty to Weirton, W.Va.

Many of the churches transmit sermons via video from one site to the others. At Orchard Hill, Mr. Haldeman does preach live on some Sundays, while at Amplify, Jason Howard preaches in person every Sunday at the Strip District campus, where he is lead pastor.

And as with other trends in recent decades, the megachurches are setting an example even for those that don’t hit the arbitrary 2,000-a-week threshold. Amplify Church has about 1,600 attending on a typical weekend at its three sites in Plum, the Strip and Indiana Borough in Indiana County. That includes 350 to 400 at its Strip District campus, which was launched in 2012 and now has two Sunday services.

Mr. Howard said some worshipers live nearby, others drive in from the suburbs to the Strip District location. Passersby poke their heads into the building and ask if it’s a dance club, given the dimmed lights, amped-up music and neon signs. Helping to answer that question is a Gothic-arched stained-glass window, what Mr. Howard calls a “postmodern shoutout to church.”

Members said they sometimes miss the fellowship of the larger church, but they still feel connected.

“It’s cozy, and it’s home,” said Miranda Ganoe of Crafton, who said she felt led by God to find the Amplify campus. “It’s what I needed. Just the energy here, and it’s a family.”

The multisite trend looks only to grow. Allegheny Center Alliance Church in the North Side has grown steadily over the decades as it has pursued strong urban and interracial commitments. It is now considering similar work in other locations.

“We’re not doing it to increase our statistics,” said pastor Rock Dillaman. “We’re doing it because we sort of hit the wall in terms of our potential on two acres in the North Side.”

New locations would be “racially diverse, economically challenged, or both,” he said. ”It’s just our whole DNA, our approach to ministry.”

Peter Smith: petersmith@post-gazette.com or 412-263-1416; Twitter @PG_PeterSmith.

First Published: January 3, 2016, 5:00 a.m.