Although the Newberry Library was officially opened in November of 1893, portions of the interior structure were not finished until the 1940's when further space was required. In addition, as needs and technology changed, renovations of existing rooms and systems took place. Major projects have included the 1895-1897 renovation of the heating and ventilating systems, the 1899 and 1923 Trustee Room remodellings, the 1925-1926 Ayer Vault construction, the 1944-1946 fifth floor completion and other repairs, and the 1960-1962 air conditioning installation and other interior remodelling.

Includes building contractors' proposals, contracts, financial statements, correspondence, specifications, and progress reports for major and minor remodelling projects.

For photographs of Library renovations, see Record Group 15/01/03.