The 179D Cliff: Why Commercial Energy Projects Should Begin Construction Before June 30, 2026
The 179D Energy Efficient Commercial Buildings Deduction, ranging from $0.50 to $5.00 per square foot post-IRA, sunsets for projects that have not begun construction by June 30, 2026. Here is the math, what 'begun construction' means in practice, and how owners are stacking 179D with other incentives in 2026.