Wednesday, the first day of school in Mercer Island, was filled with the usual excitement and jitters of seeing old friends and getting to know new teachers.

But for the first through fifth graders at Northwood Elementary, it was also a day to explore their brand new building — the fourth elementary school in the district and the first new school constructed on the Island in more than 50 years.

There are new playgrounds, outdoor areas, classrooms and shared learning spaces. A commons area for eating, reading and gathering was used by the PTA for a “welcome coffee” for families on Wednesday.

Excited students peered through the windows of the building before lining up outside, as teachers met them and walked them to their rooms. Mercer Island School District Superintendent Dr. Gary Plano said the morning brought back “wonderful memories” of his first days of school.

Cindy Goetzmann, Northwood PTA president, said that she is looking forward to helping build a culture and establish new traditions with the staff and the “melded” PTA from the Island’s other three elementary schools. Attendance boundaries in the district were redrawn to accommodate Northwood.

“We’re going to incorporate the best of what we loved and add something new,” Goetzmann said, noting that some ideas include a spring concert and a school-wide “marketplace” program.

The school’s gym includes a high school-sized basketball court. Part of the gym floor of the old North Mercer junior high, which was torn down to make room for the new school, was reused as the top of a conference table in Northwood’s administration wing.

Northwood also houses the district’s early childhood special education program, which used to be in the basement of the PEAK building.

Northwood serves about 400 students in grades pre-K to 5. Mahlum Architects of Seattle designed the school, and Bayley Construction of Mercer Island was the general contractor. Aimee Batliner-Gillette is principal and Jill Ravenscraft is associate principal.

Families can share their first day of school memories on social media with the hashtag #MIFirstDay.