Shared spaces are today’s savvy answer to the high costs of real estate, renovation, and building maintenance. And while we usually think of shared spaces in terms of co-working complexes such as WeWork, two Israeli institutions have put a new spin on this efficient concept — with help from supporters in New Jersey.

On December 20, Russell and Nina Rothman of Hackensack were in Jerusalem for the opening of the Levi Eshkol Museum and Gardens, once the official residence of Israeli prime ministers David Ben-Gurion, Levi Eshkol, and Golda Meir.

Mr. Rothman is co-chairman of American Friends of the Society for the Protection of Nature in Israel, which raised a large portion of the funds needed to renovate the 1933 structure, whose two upper floors and courtyard have now become the Jerusalem Community Branch of the Society for the Protection of Nature in Israel (SPNI).

Israel’s largest and oldest environmental organization, in search of new Jerusalem headquarters since 2012, plans to create a hub for social environmental activities with an ecological pool and a “living wall” covered in locally sourced greenery.

“The house is in the Rechavia section of Jerusalem, a very beautiful neighborhood,” Mr. Rothman said, after his return home from Israel. “When we last visited the house two years ago, it was abandoned and neglected, and the grounds were a mess. Today, it resumes with its original splendor and the grounds are beautiful; a true oasis in the heart of the city.”

Leon Sokol

Leon Sokol

The ribbon-cutting ceremony began with a tour of the building, followed by speeches from Eshkol family members and dignitaries including Israel’s President Reuven Rivlin, Jerusalem’s Mayor Nir Barkat, Labor Party leader Isaac Herzog, Jerusalem Affairs Minister Ze’ev Elkin, and Sara Netanyahu, who was representing her husband, Prime Minister Benjamin Netanyahu.

Speakers noted that the building’s new dual purpose makes sense because Mr. Eshkol, prime minister from 1963 until his death in 1969, was a champion of environmental and urban planning issues.

“President Rivlin spoke fondly of Eshkol, and said that he had a long history with the house as well,” Mr. Rothman said. “When he was a kid, he and his friends used to play soccer in the yard, and he remembers Mrs. Ben-Gurion running out to scold them and chase them away while her husband napped.”

Golda Meir used to serve homemade cake to members of her cabinet during meetings held in the kitchen, which has been restored to its early 1970s look.

Mr. Rothman’s connection with ASPNI, the American branch, goes back to that same decade. After completing a master’s degree project at the University of Minnesota on the subject of lone wolves, he came to study wolves in Israel with the help of Dr. Heinrich Mendelssohn, then head of zoology at Tel Aviv University.

The library and resource room at the Eshkol Museum.

The library and resource room at the Eshkol Museum.

“Mendelssohn was one of the founders of the SPNI, and one of the most interesting men I ever met,” Mr. Rothman said. “He connected me with the SPNI, which oversaw a network of field study centers throughout the country, and I parked myself at one in Hazeva, down in the Negev.”

(Side note: Dr. Mendelssohn was the official zoologist accompanying a supposed bird-watching trip — actually a clandestine reconnaissance mission — to the Negev led by young Shimon Perski in 1944. Dr. Mendelssohn spotted an eagle nest and suggested that the future president of Israel adopt the Hebrew word for eagle, “peres,” as his Hebraicized surname.)

A few years after ASPNI was founded in New York in 1986, Mr. Rothman readily agreed to join its board. He remains passionate about spreading recognition of SPNI in the United States.

He now shares the ASPNI chairmanship with Leon Sokol, an attorney from Teaneck who manages the New Jersey practice of the Cullen and Dykman law firm and serves on the boards of the Jewish Federation of Northern New Jersey and its endowment foundation, the Jewish Home at Rockleigh, and the Jewish Home Family.

Mr. Sokol took a pivotal role in raising about $1 million from American donors toward the renovation of the past prime ministerial residence. The project was led by the Yad Levi Eshkol memorial fund.

“Levi Eshkol, in my opinion, was the second greatest prime minister after Ben-Gurion,” Mr. Sokol said, citing Mr. Eshkol’s foresight in establishing the national electric grid and the decisions he took during the 1967 Six-Day War.

Nina and Russell Rothman

Nina and Russell Rothman

Mr. Sokol was helped in his fundraising task by his friend State Senator Bob Smith of Piscataway, chairman of the New Jersey Senate Environment Committee.

“Several years ago, at my request, Bob joined as an honorary member of the ASPNI board,” Mr. Sokol said. “He is a strong supporter of Israel, having traveled to Israel with his wife, and took a second trip with the ASPNI board to Israel two years ago. During that trip, we both inspected the former prime minister’s home that eventually became the Levi Eshkol Museum before construction had started, and were able to determine the extent of renovations needed and the plans for renovating the building.”

The two men approached developers, personal friends, and clients, sharing their enthusiasm about the importance of creating the Levi Eshkol Museum and SPNI hub. The Joseph and Cheryl Marino Family Foundation of River Edge was among the local donors.

The newly reopened house features a ground-floor interactive exhibition in English, Hebrew, or Arabic on the life story of Mr. Eshkol, who managed the Six-Day War from the building’s home office.

“While the museum allows for an exclusive look into Israel’s history, the social-environmental activism and conservation work being implemented under the same roof by SPNI’s Jerusalem Community Branch ensures the future of Israel’s nature,” said Iris Hann, the organization’s newly appointed chief executive officer.

“It is our hope that local residents, students, and tourists from around the world take advantage of everything that this unique educational and cultural site has to offer.”

To learn more and plan a tour, email international@spni.org.il.