The main library most recently underwent renovation, and a modern building addition significantly expanded the overall branch in 2009.

In 2020 the CPL sought to partially fund the establishment of the Community based - Cambridge Public Library STEAM Academy.

It was built in 1888 with land and full construction funding donated by Frederick H. Rindge, a Cambridge native and philanthropist.

[17] In the late 1960s, a more contemporary addition of plain brick exterior was created at the rear of the main library.

The newly expanded building consists of a $90 million expansion and renovation of the earlier library, led by the Boston architectural firms William Rawn Associates and Ann Beha Architects.

[27] The surrounding park and lawn grounds of the Joan Lorentz Park found at the main building is a popular meeting place for various interest groups, including pickup soccer, slacklining, book and religious study groups, casual picnics, and the traditional practice of various martial and therapeutic arts.

The Saturn model was packed up and shipped back to the Museum of Science and was not positioned at the reopened renovated library.