Children's Hospital of Philadelphia will announce on Tuesday its biggest gift ever: $50 million toward the $425 million cost of an outpatient center rising on the institution's University City campus.

The Buerger Center for Advanced Pediatric Care, named for a family that owns a Fort Washington financial-services firm, will become the hub for complex outpatient care in the hospital's network in Southeastern Pennsylvania and New Jersey.

The donation is part of a $100 million capital campaign to help pay for the facility, expected to open in 2015. Remaining costs will be paid through additional philanthropy and money from operations.

Spearheading the family's gift was Reid Buerger, who said his view of Children's, frequently ranked among the best of its kind nationally, took on deeper significance when he was looking forward to fatherhood several years ago.

"It wasn't really until my wife became pregnant with our first child that we thought of what Children's Hospital could mean to her, to her peers, to her kids in the future, really, to the community," Buerger said Monday. Buerger's children are now 3 and 1.

As a philanthropist, Buerger, 37, decided to get involved at Children's, eventually joining the board of directors in September.

"The more time I spent with the board and the more time we spent with the staff at CHOP, the more impressed we became," he said.

Supporting what became the Buerger Center exemplified the family's philanthropic goals, he said, "because it could touch so many children and so many families and have such a profound impact."

The Buerger Center will bring the hospital's investment in new facilities on the site of the former Civic Center to more than $1.1 billion, according to projections in a 2011 bond prospectus. That included $504 million for the Ruth and Tristram Colket Translational Research Building completed in December 2010.

The $25 million donated for the research building by the Colkets, whose wealth stems from Campbell Soup Co., had been Children's largest.

The University of Pennsylvania has spent an additional $1.1 billion on Civic Center Boulevard, helping to create what is becoming a medical megalopolis.

Children's Hospital chief executive Steven M. Altschuler said the Buerger gift toward a 700,000-square-foot, 12-story outpatient facility underscores "the importance and significance of the Children's Hospital of Philadelphia to this region."

The Buerger Center - which will include a 14,000-square-foot rooftop garden for recreation and therapy and a 2.6-acre landscaped outdoor plaza - is designed to make things easier for patients who must see a series of specialists during one visit.

"This is a concept for medical care that will be state of the art and will lead transformation in other health-care providers," Altschuler said.

A child needing comprehensive neurological care, for example, will be able to see a psychiatrist, child-development specialist, neurologist, and psychologist without walking far because those specialists will be concentrated in "neighborhoods" within the building.

Electronic systems will alert doctors and other personnel to the arrival of patients in the underground parking lot, helping to reduce waiting times, officials said.

Buerger, a cofounder with his parents of Coventry Group Inc., which pays individuals cash for life-insurance policies and life settlements and then sells them to investors, started the ball rolling on the gift to Children's, but it is from his entire family. The group includes his parents, Alan and Constance; his wife, Krista; and his brother, Grant.

"It was really a family endeavor," he said.