By any measure, the southwest portion of Butler County has been growing, but not every area has shown the same rate of expansion — and some may have reached their limit.

Leslie Osche, a Butler County commissioners chairwoman, said the county’s southwest section “is booming with new housing starts, infrastructure investments, and business growth.”

“The (Interstate) 79 corridor is ripe for logistics and transportation development such as FedEx and UPS,” she said. “This corridor connects to major interstates on the East Coast including Interstates 70, 80, 90 and the Pennsylvania Turnpike.

“This is where Butler County shines in offering an affordable quality of life through low taxes and a dedicated workforce.”

Osche pointed out Cranberry Township is “the envy of most counties, with the Lemieux Center Complex and Cranberry Springs at its core.”

She cited the longtime presence and subsequent establishment of safety manufacturer MSA Safety’s world headquarters along with Westinghouse’s nuclear operations in the township “makes us a leader in energy and safety.”

Dan Santoro, Cranberry Township manager for the past four years, said the township has become a regional hub for area corporations.

“More people commute into Cranberry Township than leave to work in other places,” he said.

Jerry Andree, former Cranberry Township manager from 1990 to 2021 and present facilitator for the Southwest Butler County Stormwater Planning Group, said corporations such as Emerson Electric and Giant Eagle situated their corporate headquarters in the township.

Andree credited the plans the township officials drew up in the 1990s that created high-quality office parks such as Cranberry Woods and Cranberry Springs.

“Corporations relocated to Cranberry Township because of the planning the elected officials did here, focusing on creating family-sustaining jobs. They are coming from Allegheny and Butler counties.

“Of course, Cranberry Township has benefited from its location, but we’ve maximized that location,” Andree said.

Since 2003, Cranberry Township has averaged about 473 new residents annually, the equivalent to about 1.7% population growth year over year, Santoro said in a June interview.

With the township’s spike in population, he said at that time, it was not surprising to see U.S. Census data showing Butler County as one of only two counties in Western Pennsylvania and 23 counties statewide to see its population increase in 2023.

Santoro said the township’s growth was spurred by its proximity to the Pennsylvania Turnpike, Route 228 and I-79.

Increased commuters from outside the township have brought increased traffic. Andree said the township has developed a state-of-the-art Traffic Management Center to ease congestion on the township’s highways and streets.

“We’re very aggressive in managing traffic,” Santoro said. “We have a smart traffic signal system to manage traffic flow.”

That increased traffic isn’t confined to Cranberry Township.

“We function as a region,” Santoro said. “Transportation infrastructure doesn’t stop at the township line.”

He said the ongoing Route 228 Corridor project, when completed, will spur development when the widening of 228 is completed.

“We can see that happening, moving into Adams and Middlesex townships all the way out to the Route 8 intersection,” he said.

According to U.S. Census projections, the 2024 population of the township is just over 35,000. Andree said the population is expected to increase to 40,000 in the near future, and the township is working to manage that growth.

Cranberry isn’t done growing, Santoro said.

“There’s no reason to believe (population growth) will accelerate or decelerate,” he said.

While many municipalities in southwestern Butler County plan for increasing growth, Seven Fields, a borough situated within Cranberry Township, is “pretty much built out,” said Tom Smith, borough manager.

There is little to no housing growth left on the horizon for his borough.

The last residential building was the High Pointe town houses this year. It’s an enclave of town houses on High Pointe Drive.

“It’s a small-scale population, but it seems that it’s a desirable place to be. We have had no tax hikes in 14 years,” said.

And the houses that are there, he said, sell fast. The average price of a house in Seven Fields, he said, is $700,000, but that seems to be no deterrent.

“For a house sale, the average turnaround time is about a week,” Smith said.

Meanwhile, Cranberry and Adams Township leadership say accommodating population growth, planning housing for future residents is essential for their respective municipalities.

Santoro said the township’s housing is a mix of single-family homes, town houses and retirement patio homes.

“We have a little bit of everything going on in the township,” Santoro said.

In neighboring Adams Township, Gary Peaco, the township manager for the past six years, said the township has a population of 14,844 and “is pretty heavily residential” with a mix of single-family homes, quad houses and townhomes. “There are some apartment buildings, but not a lot,” he said.

While there are still residential properties in the township that could be developed, Peaco said the township has “fairly strict zoning in place.”

The township is not a high-density populated area, although Peaco said the township’s population, similar to Cranberry Township, is projected to balloon to 25,000 to 30,000 in the next 20 to 30 years.

Jackson Township is another southwest Butler County township that has been growing. Chris Rearick, manager of Jackson Township since 2011, has seen the nearly 22-square-mile township’s population reach 6,500.

Rearick said according to the township’s 2017 comprehensive plan the township projects 100 to 150 housing units added annually along with an additional 300 to 350 residents.

Rearick said the first wave of housing, beginning in 2014, was largely single-family detached housing, but in the last four to five years there has been an increase in the construction of townhomes, quad homes and duplexes.

“There have been apartment proposals near Route 19 that have been approved, and construction should start next year,” Rearick said.

“We’ve seen both residential and commercial growth, retail and restaurant growth.”

He pointed to the township’s Jackson’s Pointe Commercial Park and the Sippel Commercial Park with its FedEx operation, both on the east side of I-79, as examples of commercial development.

“There are also other facilities with manufacturing, distribution and technology,” in the two commercial parks, he said.

Rearick said the township’s location is driving its growth, especially its proximity to Cranberry Township and Allegheny County to its south and the Interstate 79 and Routes 528 and 19 corridors.

He added the increase of revenues and impact fees levied on new construction has allowed the township to keep up with infrastructure improvements.

While Cranberry Township has enough employers for its residents and commuters, and Jackson Township builds its future employers, Lancaster Township manager Mary Hess doesn’t see the same business development in the township, the northern most of the three municipalities stacked atop each other in southwestern Butler County.

Hess, the Lancaster Township manager for nearly a year, wears many hats. As well as overseeing the five full-time members of the township police department, the three-member road department and three administrative employees, she also serves as the township treasurer.

She describes the township, which has a population of 3,000 as “more or less a bedroom community.”

“There are large parcels of land owned by families,” she said. “There are a lot of horses, a lot of open space.”

Most housing is single-family homes with a few apartments or duplexes.

In addition to a large dairy farm, Hess said businesses on the southern portion of the township include Burrow Equipment Rental and Sales, Wack Trailers, Butler Refrigeration, Insight Pipe and Graff Custom Construction.

In addition, she said, the township is home to the Arden Woods housing development of 325 single-family homes which began construction in 2019. It includes 18 quad homes for residents 55 and older.

There is also the Strawberry Ridge Golf Course as well as private businesses interspersed through the township.

Route 19 is the primary route in the township, she said, because I-79 has no exits leading to the township. The township has just started contemplating a Route 19 corridor improvement project.

She said the population of the township is expected to increase to 3,500 by 2030.

Forward Township has also been experiencing population growth, if at a slower rate than some of its neighbors.

Lindsey Berry, the township secretary since 2016, said the 23.4-square mile township since 2016, said the 23.4-square-mile township had a population of 3,164 according to the 2020 U.S. Census.

Since then, Berry said, the Hidden Acres development with 26 to 30 homes and the Meadows Ridge Phase IV development with 26 homes, both located off Route 68, have been added since the Census. She noted the Census indicated that 11.5% of the township’s population are military veterans.

Berry said Forward Township is mostly rural with a lot of farms and a few small business in the township.

In stark contrast to the municipalities surrounding Mars, the borough named for the red plant is seeing its population in decline.

The 2020 U.S. Census put Mars’ population at 1,458, a drop of 14.2% from the 2010 population of 1,699.

Mayor Greg Hartung said the challenge is to maintain “where we are in terms of population, it’s a challenge when we are a 130-year-old borough in the middle of suburbia.”

Describing Mars, Hartung said, “I would say it is a cross section. It’s somewhat of a bedroom community. It’s a small town with a retail section, but it also has manufacturing.”

There are machine shops of different types that can be seen down Clay Avenue in the borough.

“St. John’s Home is the largest employer,” the mayor said. “It’s a nursing home and everything that goes with that type of a facility.”

The housing in Mars, which takes up 0.47 square miles, is a mix of single-family homes, duplexes and rental apartments. Residents travel to jobs in Cranberry Township, Butler and Pittsburgh, Hartung said.

“There is a small percentage of land that could be developed,” Hartung said, but added there is nothing in the works at present.

Thomas Oliverio, the mayor of Zelienople since 1990, has seen the borough change in countless ways over his time in office.

Oliverio said the borough of nearly 4,000 people was once a blue-collar town featuring manufacturing opportunities.

“There’s still quite a bit of that here, but 10 to 15 years ago it began changing,” he said.

Today, he said most of the businesses along the town’s Main Street are women owned and cater to female shoppers.

“Women are here for the shopping: candles, women’s clothes, women’s shoes,” he said. “And there are the restaurants.”

Harmony, located so close to Zelienople that one October festival features transportation between the two boroughs, often sees tourism, too, Greg Such, council president said.

“This is a bit of a tourist destination because of the Harmony Museum, the historic buildings, there’s a little bit of shopping, good restaurants and coffee shops, Union Brothers Brewing,” Such said.

There are two large businesses in Harmony, Robinson Fans and TRANSTEX, formerly U.S. Liner, Such said, but most residents travel outside Harmony to work.

“I don’t have a good feel for that part, exactly where they go, but the average travel time to work is 20 minutes so it’s relatively local, maybe Cranberry Township,” he said.

Harmony has a mix of single-family houses, including 20 historic houses built in the Federalist style that date to the early 1800s, Such said, reflecting Harmony’s founding in 1804 by the Harmonist Society, a group of German religious dissidents.

Such said the half-mile square borough, which has shy of 1,000 residents, has pretty much grown as much as it can.

“We’re built out. Our population has been steady over the last three Censuses,” he said. “We are getting younger. We could conceivably grow, but we’re pretty built out.”

Zelienople has a combination of single-family homes, town houses and quad homes, Oliverio said.

“Most of them, believe it or not, are being rented out. We have a lot of renters,” said Oliverio. “Zelienople is a community of homes that are expensive. People buy them and rent them out.”

He said a new housing development being built along Route 68 will bring, he estimated, an additional 600 people to Zelienople when finished.

And that may be the end of growth in the 1.5-square-mile borough.

“We are pretty well developed. I don’t know if they can do anymore after this development,” Oliverio said.