William M. Greenhouse Jr., 89, formerly of Huntingdon Valley, a commercial developer and devoted single father, died Monday, Jan. 8, of dementia at Rydal Park, where he had lived for the last seven years.

William M. Greenhouse Jr. at son Jeffrey’s wedding in 2008.
Courtesy of the family
William M. Greenhouse Jr. at son Jeffrey’s wedding in 2008.

Born to Rita Bigar and William M. Greenhouse, he graduated from Cheltenham High School.

Soon after graduating, Mr. Greenhouse began to follow the career path of his father, a Philadelphia-area developer. He learned the older man's construction techniques, and that exchange of knowledge paved the way for a lengthy business partnership.

In 1950, Mr. Greenhouse graduated with a bachelor's degree in architectural engineering from the University of Pennsylvania, his father's alma mater. While at Penn, Mr. Greenhouse was a member of Sigma Alpha Mu fraternity.

Starting in 1951, he worked with his father to develop, sell and manage commercial properties in Philadelphia and the suburbs. An example of their work is a string of commercial buildings adjacent to Einstein Medical Center in Olney.

William M. Greenhouse Inc., as the business was called, was home-based and later operated in conjunction with Larry Snyder Inc. of Jenkintown.

His father was known for conducting the enterprise with "fairness and trust," said son Jeffrey. His father retired in 2006 at age 78, Greenhouse said.

William M. Greenhouse Jr. and Kathryn Adelberg Greenhouse on their wedding day in 1974. They had a son before she died in 1987. .
Courtesy of the family
William M. Greenhouse Jr. and Kathryn Adelberg Greenhouse on their wedding day in 1974. They had a son before she died in 1987. .

In 1974, he married Kathryn Adelberg, a social worker who created drug treatment programs for mothers-to-be and their infants. The couple settled in Huntingdon Valley, in a house dating back to the 1740s.

It was a fixer-upper, with a main residence, a carriage house with garage, a loft apartment, and a workshop. Enthralled by the property, which included several massive sycamore trees and a decaying swimming pool, Mr. Greenhouse began a rebuilding project.

"He used his skills and his own hands to lovingly renovate the buildings and the grounds, turning the swimming pool into a fish pond, and eventually overseeing the construction of a horse barn and paddock on the property," his son said. Kathryn Greenhouse kept horses and rode them there.

A family snapshot of William M. Greenhouse Jr. with his toddler son Jeffrey.
Courtesy of the family
A family snapshot of William M. Greenhouse Jr. with his toddler son Jeffrey.

"It was a nice property to grow up on," said his son. "You're in the city suburbs, but it looks like you're out in the country."

In 1987, Mr. Greenhouse's wife died of cardiac arrest at age 42, plunging him into the world of single parenthood. She had not been ill.

Mr. Greenhouse had lost his own father and mother relatively early in life, so he had known tragedy, but it didn't defeat him. Instead, Mr. Greenhouse focused his energy on rearing his son, then 11. The two stayed on the Huntingdon Valley property together.

"He was an entirely dedicated dad, and that was the main thing about him," his son said. "I didn't realize until a few years ago, when I took over the family affairs, how much he had done to smooth the way for me.

"He made numerous personal sacrifices to ensure that I could recover from the tragedy and attend the college of my choice," his son said.  Following the family pattern, that choice was Penn.

Mr. Greenhouse loved to travel and always packed his camera. "His talent really came through," his son said, in the photographs he took while touring Portugal, Spain, Morocco, France, Suriname, Trinidad and Tobago, and Curacao.

An accomplished skier, Mr. Greenhouse tackled the slopes designated for advanced skiers in New England, Canada and the French Alps. He was an avid golfer with a 7 handicap, and a longtime member of the Philmont Country Club in Huntingdon Valley.

In addition to his son, Mr. Greenhouse is survived by two grandsons and a sister.

At his request, there will be no memorial service. Burial was private.

Donations may be made in his name to the Pennypack Ecological Restoration Trust via https://pennypacktrust.org/. The nonprofit is dedicated to protecting the 812-acre Pennypack Preserve, a natural area in Huntingdon Valley. Mr. Greenhouse supported the trust and served on its board.