Sage Hill School welcomed about 140 seventh- and eighth-graders to its Newport Coast campus on Aug. 17, opening a middle school division for the first time in the private school's 26-year history.

Head of School Patricia Merz and Board of Trustees Chair Mike Bolen cut a ceremonial ribbon in front of students, parents, faculty and trustees on the first day of the 2026-27 school year, according to Stu News Newport. The addition makes Sage Hill the only independent school in Orange County serving grades 7 through 12. Total enrollment now stands at approximately 730 students.

The new 38,658-square-foot building houses middle school classrooms, offices, a café and the campus's second gymnasium, which seats about 1,000 people, the Orange County Register reported. The Register put the building's cost at $55 million. It is the school's seventh building on its 28-acre campus and broke ground in late 2024.

Sage Hill launched a $25 million capital campaign in 2023 to support the construction and to fund increased tuition assistance, according to Stu News Newport. The ribbon cutting capped more than five years of planning, fundraising, design and construction.

Director of Middle School Dr. Joseph Moody and Student Council President Christian Lu, Class of 2027, also spoke at the ceremony.

Wendy Rogers, chief executive of LPA Design Studios, the Irvine-based architectural firm that designed the building, told the Orange County Business Journal in August that she attended the ribbon cutting. "It was a bit of a teary moment, if I'm being honest," Rogers said. "It was 30 years ago I was walking across the snake ridden landscape, talking about what that school would be."

LPA's relationship with Sage Hill dates to 1966, when the firm master-planned and designed the school's original campus, the Business Journal reported. Rogers said LPA helped the school's founders find leftover land from Irvine Co.

Irvine Co. donated the campus site when Sage Hill was founded in 2000, according to a company article published Oct. 14. That article said the company also provided 20 acres for Newport Harbor High School in 1929 and land for Corona del Mar High, Newport Coast Elementary, Ensign Intermediate and Lincoln Elementary over the years.

School officials told the Register there were always plans to add a middle school when the high school was founded. The new gym will also host pep rallies and Sage Center Service Learning Days, a school spokesperson said.