Sidwell Friends announced Tuesday that the school plans to consolidate onto a single campus in the District after the administration signed an agreement to purchase an adjoining property in Northwest Washington.

The elite private school announced that it plans to buy a 5.7 acre site bordering the north side of its campus along Wisconsin Avenue, a property currently occupied by the Washington Home assisted living facility and hospice.

Sidwell, founded in Washington in 1883, has an enrollment of 1,149 students and has educated generations of children from Washington’s most affluent and influential families, including President Obama’s daughters Sasha and Malia, as well as Chelsea Clinton, Julie and Tricia Nixon and Archie Roosevelt.

School officials wrote in a letter to parents that the new property will grow the campus to a total of 22.7 acres and allow Sidwell to share a single campus for the first time since 1963, when the elementary school grades moved to Edgemoor Lane in Bethesda, Md.

“The resulting continuity and strengthened sense of community will improve the Sidwell Friends experience for generations to come,” Head of school Bryan Garman and board of trustees clerk Margaret Plank wrote in the letter. “The acquisition of The Washington Home site will also allow the School to create new shared community spaces for our Middle and Upper School students, and attend to a long-overdue renovation of the Upper School building.”

The Sidwell leaders wrote that the purchase will be completed through philanthropy, and the new lower school in the District is scheduled to open in the fall of 2019.

Under the new plan, students currently in grades 1 through 4 will finish at Bethesda while students in Pre-K and Kindergarten will move to the new campus starting in their 3rd and 4th grade years respectively, the school officials wrote.

“All divisions will benefit from the creation of shared community and dining spaces—and from being part of one community on one campus,” Garman and Plank wrote.

Tim Cox, the CEO of the Washington Home and Community Hospices, wrote an open letter about the transaction on the home’s Web site. He said that because the sale won’t close until the end of 2016, there will be time to develop “individual transition plans for our residents and our staff.”

“There are no changes to our long-term residential care and inpatient hospice services today, or in the near future, at our Upton Street location,” he wrote.