Reopen and Rebuild America's Schools Act of 2021 This bill provides support for long-term improvements to public elementary and secondary school facilities. First, the bill sets forth allocations to states and establishes a need-based grant program for local educational agencies (LEAs) to improve school facilities. Further, the bill specifies allowable uses of grant funds, including carrying out major repairs, improving indoor air quality, and making facilities accessible to disabled individuals. Additionally, the bill requires LEAs that receive funds for new construction, modernization, or renovation projects to comply with hazard-resistance building codes and performance criteria under the WaterSense program of the Environmental Protection Agency. Further, the bill requires LEAs to adopt certain green practices (environmental standards) and requires the use of iron, steel, and manufactured products that are made in the United States (Buy America). The bill restores school infrastructure tax credit bonds. The bill also sets forth reporting requirements, including annual reports on grant program projects and a report by the Government Accountability Office that requires a study of the geographic distribution of projects, the impact of projects on student and staff health and safety, and the accessibility of projects to high-poverty schools. Next, the bill extends through FY2026 the Impact Aid Construction program. Finally, the bill establishes a grant program to assist LEAs with repairing or replacing concrete foundations affected by pyrrhotite (an iron sulfide material linked to crumbling foundations).