The library transferred its holding of blueprints and building plans, circa 1900-1969, to the City of Boston Archives. For more information about the collection, see the City of Boston Archives Guide for accessing building plans,
For any building plans from 1970 to present day, please contact Inspectional Services Department (ISD) by calling 617-635-5300 and asking for the document room. The ISD staff should be able to tell you if the plans are microfilmed or stored elsewhere in their document management system.