The proposed project includes the expansion of Portola High School in the City of Irvine, within the existing campus. Currently, the enrollment capacity is 2,600 students. The proposed project would increase the school’s capacity from 2,600 to 3,400 students to accommodate increased enrollment in the future. The proposed project includes the development of a 27,071 square foot education building in the center of the campus. The new building would be 2-stories in height and consist of 14 classrooms, two science classrooms, two teacher collaboration rooms with adjoining conference rooms, four offices, one workroom, two data rooms, two electrical rooms, two main student restrooms, one breakroom, six single use restrooms and two student common areas. The proposed project also includes the addition of 6 portable classrooms to the center of the campus, which would be located to the south of the new building. The placement of the new education building would require the relocation of several sports fields, including: the junior varsity softball field, varsity softball field, material storage, batting/pitching cage, soccer field, practice soccer field, and the shot put. No sports lighting will be added or modified as part of this project. The proposed project would also include associated site improvements to walkways, fencing and utility hooks ups. Construction will be conducted in two phases between January 2024 through August 2025. The proposed project will analyze environmental impacts as compared to the 2013 Certified SEIR, which will be referred to as Certified SEIR in this addendum.