From 1894-1910 Lower Merion High School was in a stone building located on a property it shared with the Ardmore Ave. Elementary School on the south side of Ardmore Ave. between West Athens and School Lane, Ardmore. The school burned in 1900 but was rebuilt, also of stone. From 1910, when the high school moved to new quarters, until it closed in 1963, the Ardmore Avenue school served as an elementary school.
The second school, was located at 245 East Montgomery Ave., Ardmore. The site is shared with the Lower Merion School District Administration building, bus garage, Clarke house, and from 1922-1992 the Lower Merion Township Junior High School (renamed Ardmore Junior High School). In 1912-13 twenty-one staff members were employed under principal "Professor" Charles B. Pennypacker. In 1933 the site contained 17 acres. In 1939-40 George H. Gilbert was principal with a teaching staff of sixty-one. About 1943 an adjoining, stone "technical" building was added along the School House Lane side. It contained shops such as auto repair, metal, print, wood-working, drafting, etc. Since the 1990's some rooms in the former Technical Building have been used for art classes. In 1950 a cafeteria/library wing was added toward Pennypacker athletic field. It was designed by Savory, Scheetz and Gilmour while the general contractor was Frank V. Warren, Inc. That same year the General H. H. Arnold athletic field was opened across Montgomery Ave. The 1910 granite and limestone building was demolished in 1963 when the present, air-conditioned structure was erected, which was designed by H.A. Kuljian and Co., while the general contractor was S. Levy Co.
By 1957, the enrollment had grown to 1,663 students in the tenth, eleventh, and twelfth grades, and the time had come to build a second high school in Lower Merion Township. In 2000 the approximate student enrollment was 1200.