This document is Addendum 3 to the Request for Proposal (RFP) for the Ames Infrastructure Modernization Project, Solicitation Number RFP-SC-25-637, issued by the U.S. Department of Energy's Ames Laboratory. The RFP seeks to acquire general construction services for infrastructure modernization at the Ames National Laboratory facility in Ames, Iowa. The addendum provides clarifications, changes, and additional information related to the original RFP. Key details include the proposal due date of October 29, 2024, and the intent to award one subcontract as a result of this solicitation. The RFP and addendums are available on the Ames Laboratory website.