What are commercial buildings actually claiming? Real data from 179D calculator submissions.
| Building Size | Avg. Deduction (Estimated) | Avg. Per Square Foot | Maximum Possible | Assessments |
|---|---|---|---|---|
| Large (>100k sqft) | $312,000 | ~$2.34/sqft | Up to $847,500 | 1* |
| Medium (25k–100k sqft) | $118,000 | ~$1.88/sqft | Up to $353,125 | 1* |
| Small (<25,000 sqft) | $42,000 | ~$1.68/sqft | Up to $141,250 | 1* |
* Categories with fewer than 10 real assessments use IRA baseline calculations
The Inflation Reduction Act of 2022 significantly expanded 179D. The deduction now scales from $0.50–$1.00/sqft (base) to $2.50–$5.65/sqft for projects meeting prevailing wage and apprenticeship requirements. For tax-exempt entities (schools, government), the deduction can be allocated to the designing architect or engineer — creating a strong incentive for energy-efficient public building design.
Enter your building's square footage and planned upgrades to see your potential 179D deduction
Calculate 179D Deduction → All IncentivesSection 179D of the IRC allows commercial building owners and tenants to deduct the cost of energy-efficient improvements from federal taxes. Under current IRA rules, the deduction ranges from $0.50 to $5.65 per square foot of improved space, depending on the percentage energy reduction achieved and whether the project meets prevailing wage and apprenticeship requirements.
Qualifying systems include: HVAC (heating, cooling, ventilation), interior lighting, and building envelope (insulation, windows, roof). To claim the deduction, a qualified engineer must certify that the improvements reduce energy costs by at least 25% compared to the ASHRAE 90.1-2007 baseline. Full deduction requires 50% reduction.
Tax-exempt entities (federal, state, and local government, nonprofit organizations) cannot claim the deduction directly because they don't pay income tax. However, they can allocate the deduction to the designer — the architect, engineer, or contractor responsible for the energy-efficient design. This allocation mechanism makes 179D a valuable incentive for energy-efficient public building design.
The basic formula: Deduction = Qualifying sqft × Rate per sqft. The rate is $0.50–$1.00/sqft for 25–49% energy reduction, and $2.50–$5.65/sqft for ≥50% reduction with prevailing wage compliance. A 50,000 sqft office achieving 50%+ reduction under prevailing wage rules could claim up to $282,500 in deductions.