What documentation is required to claim the 179D tax credit?

To claim the 179D tax credit, you need detailed documentation proving that the building meets specific energy efficiency standards. This includes energy modeling reports, certification from a qualified third-party engineer, and allocation letters if the project involves a government-owned building. The documentation must demonstrate that the lighting, HVAC, or building envelope improvements meet the criteria set by the IRS. Accurate records and proper certification are essential to successfully secure the 179D tax credit and avoid any compliance issues.