The IRS maintains a page titled “Energy Efficient Commercial Buildings Deduction” which describes how the § 179D deduction works, who is eligible, and how deductions are calculated.
Taxpayers claim the § 179D deduction using Form 7205, which requires identifying whether they are the building owner or the designer, providing certification details, and specifying who is handling the allocation of the deduction.
The IRS Large Business & International (LB&I) division has issued a “practice unit” on § 179D (dated February 2025) meant for IRS examiners. This document outlines review procedures, certification requirements, and how deductions are audited.
The Department of Energy’s 179D portal and related FAQs provide supplemental guidance, including compliance pathways (modeling vs. measurement), energy savings thresholds, and prevailing wage/apprenticeship rules.
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