He served as a ship's carpenter during World War II in the Philippine Islands and Guam campaigns from 1941 to 1943. After the war, he returned to the University of Pennsylvania and graduated with honors in 1951 from the School of Fine Arts/Architecture.
Among his creations was the Glenside Library in the 1960s, which was honored by the Pennsylvania Society of Architects with its Distinguished Building Award.
He helped change the way the nation housed adjudicated youth; his design in the mid-1970s for the Montgomery County Youth Center was innovative because it was secure but resembled a school, not a jail.
"He thought that if you could get a kid into a calm environment, you could calm them down and help them," said his son. "He took a big risk by sticking his neck out and saying, 'This is what you have to do.' "
The facility - replicated nationwide - was honored by the American Institute of Architects, the National Council of Juvenile and Family Court Judges, and the American Correctional Association.
He changed the skyline of Ocean City, N.J., by designing the 10-story Port-O-Call Hotel, which opened in 1966.
Other projects were the Centralized Biological Lab on the main campus of Pennsylvania State University, Wood River Village in Bensalem, the Masonic Home in Lafayette Hill, the Elkins Park Train Station, the Good Counsel Hall dormitory at Villanova University, the Glenside Fire Department, and the Whitpain Township Building.
His favorite civic effort was work done with the Carpenters' Company of Philadelphia in 1988. The group created the Grand Federal Edifice, a 36-foot-tall domed float, mimicking one built by the same company in 1788. The original appeared in the Grand Federal Procession in Philadelphia, marking ratification of the Constitution.
The copy Mr. Clemmer helped build was featured in George H.W. Bush's inaugural parade in Washington on Jan. 20, 1989. It is warehoused in the Philadelphia area.
Mr. Clemmer was a 54-year member of the Union League of Philadelphia and a member of the Independence Hall Association, the National Trust for Historic Preservation, and Friends of Historic Rittenhouse Town. He also served on the Abington Township Planning Commission and as a historic consultant to Cheltenham Township.
He was a member of the Summit Presbyterian Church in Mount Airy, St. Paul's Episcopal Church in Elkins Park, and St. Matthew's Episcopal Church in Maple Glen.
An accomplished artist and watercolorist, he studied at Woodmere Art Museum under Howard N. Watson, a nationally recognized watercolorist and illustrator.
He and his wife, the former Mary Jane Bertolet, bred and showed bearded collies for 30 years. He was a former president of the Huntingdon Valley Kennel Club and will be honored June 1, when the club dedicates its 100th show to his memory.
Surviving in addition to his wife of 57 years and son, are a daughter, Catherine C. Pickell; five grandchildren; and a brother.
A memorial service will be at 11 a.m. Saturday, March 16, at St. Matthew's Episcopal Church, 919 Tennis Ave., Maple Glen. Friends may call starting at 10 a.m. Interment is private.
Donations may be sent to Carpenters' Company of Philadelphia, 320 Chestnut St., Philadelphia 19106.
Contact Bonnie L. Cook
at 215-854-2611 or firstname.lastname@example.org.