By 2001, the student population had grown to 275 students. The Middle School advising program was developed more fully, with students being assigned a faculty advisor in a grade-level group of about eleven students. Advisories began to meet several times each week to help support students in all areas of school life – academic, social, and emotional.
The School increased its commitment to diversity and academic excellence. The financial aid budget doubled, and the School became known for having a strong academic program that served a multiethnic, socioeconomic mix of families, reflecting the larger community of Oakland and the greater East Bay.
In the fall of 2001, Redwood Day School was granted a conditional use permit that allowed growth to 387 students, the maximum enrollment that would result from doubling the Lower School to two sections per grade. In 2002 and 2003, RDS added 11,700 square feet of classroom and multi-use space to the Lower School and 4,800 square feet of classroom space to the Middle School, replacing aging portables.
In 2004, Mike Riera became the Head of School. Under his leadership, Redwood Day School became recognized as a premier independent school, both in terms of academic rigor and social-emotional development.