The idea is to make Philadelphia a viable destination for young tech-skilled workers lured by a critical mass of start-up companies.
"Comcast can't staff that [new] building and then for the next 50 miles around it, there is a wasteland and a lack of activity," said Sam Schwartz, Comcast's chief business development officer.
"We need an active tech community in Philadelphia. We will be doing more and more of this as we move toward the new building."
He added: "We want to see tech labor here, and we want to see entrepreneurism here. We have got many more things up our sleeve."
Comcast, the nation's largest pay-TV and residential Internet provider, hosted a gala for Philly Tech Week in April at its corporate headquarters. Home for the Summer was layered onto an existing and expanded Comcast internship program for college sophomores and juniors.
Amie Ryno, senior manager of university relations, said Comcast offers about 400 sophomores and juniors paid internships in technology, engineering, finance, and general business areas. This year, 5,500 students applied, and they work mostly in New Jersey and Pennsylvania.
Comcast's plans for the new technical center - that's how Comcast folks refer to it - are taking place at a time when some of the city's economy seems to be modernizing, and its labor force is getting younger.
Earlier this year, Mayor Nutter designated a several-block, low-rent area on North Third Street in Old City as "NERD" Street.
The name was derived from N3RD, which coffee-fueled techies thought looked like NERD.
Officials say there are dozens of Web and design firms on Third between Market and Poplar Streets. Schwartz and other Comcast executives have toured the area.
"Philadelphia is putting its own case forward. It feels like everything is coming together at the same time," said Luke Butler, chief of staff for Alan Greenberger, the city's deputy mayor for economic development.
A Pew Charitable Trusts report in January listed Philadelphia as the top city in the United States for population growth of young adults between 20 and 34, so-called millennials.
Pew estimated, based on census data, that the number of young adults here jumped by 100,000 between 2006 and 2012, or 6.1 percent. The second, third, and fourth cities on the millennial growth list were Boston, Nashville, and Baltimore, with gains of 5.7, 5.6, and 5.4 percent.
Disturbingly, career prospects and jobs were the biggest concerns of Philadelphia's young adults, according to Pew's study.
Perhaps altering that mind-set will be the first five Home for the Summer interns.
Harvard freshman Michelle Danoff had second thoughts on a tech internship in Israel - perhaps a wise decision in retrospect, with the recent outbreak of serious hostilities between Israel forces and Hamas fighters in Gaza.
Her parents, who live in Center City, told her to apply to Comcast.
"Going to college gives you a new appreciation for your family," Danoff, 19, who studies computer science at Harvard, joked in an interview at the Comcast Center.
Matthew Marshall, an engineering and computer science student at Case Western Reserve University in Cleveland, sent out about 20 resumés and got a response from Comcast three days before the end of school. The Home for the Summer program was so new that when Marshall searched for it, he could find no information.
"I'll be honest," said Marshall, 19, who graduated from Downingtown High School East. "I did not think of Philly as a tech area. I had no idea."
He liked learning the corporate culture at Comcast and visiting the city's museums.
Xiayang Fan, 19, a graduate of Central Bucks High School East, is studying computer science at the University of California, Berkeley, and applied for internships in Silicon Valley. He was happy to get the Comcast internship because he does not get home to Bucks County often during the year.
Jacob Ginsparg, a graduate of Radnor High School, and Margaret Meehan, a graduate of Lower Merion High School, also are participating in the program. Comcast says it pays the interns a "competitive hourly rate." The company did not disclose that rate.
In addition to four weeks at Comcast, the interns are rotating into three smaller tech companies in the city: RJMetrics, Artisan Mobile Inc., and Solve Media.
The 76-employee RJMetrics is on the 15th floor of the Widener Building next to the downtown Macy's. The company's airy offices with dark wood floors have an open floor plan, white boards, large eating area, and a Ping-Pong table. The company helps online businesses.
"A lot of the kids leave," said Tristan Handy, 33, marketing vice president, who was hired in February 2013 as employee No. 19. "There is an intern working for us now. He is phenomenal, but he's headed out to California because they have the brand."
Handy spoke before the Home for the Summer interns rotated to his company.
He said most cities were doing what Philadelphia is attempting. "Scenes are growing wherever twentysomethings want to be," he said.