Estimate Your 179D Tax Deduction
Find out how much your energy-efficient building project could qualify for in federal tax deductions — up to $5.81 per sq ft.
How It Works:
Select your building type and project type, then enter your construction start date and placed-in-service date
Enter your total project cost and gross square footage
See your estimated 179D deduction range instantly, based on the minimum and maximum rates that could apply to your project depending on your building’s energy performance.
What You’ll Need
Building & Project Info
Your building type and whether the project is new construction or a renovation help determine your eligibility and applicable deduction rate.
Construction Timeline
Your construction start date and placed-in-service date confirm whether your project falls within the qualifying window.
Project Cost & Square Footage
The 179D deduction is calculated on a per-square-foot basis, so your total project cost and gross square footage are the primary drivers of your estimated deduction.
Does Not Qualify
Residential buildings must be 4+ stories to qualify for the 179D deduction.
i.e. Architect, Engineer, Design-Build Contractor
Does Not Qualify
For government buildings, only the designer primarily responsible for the technical design drawings can claim the 179D deduction.
Qualifies for Bonus Deduction Rate
Construction started before January 2023 and placed in service in 2023 or later automatically qualifies for the higher deduction rate without meeting prevailing wage and apprenticeship requirements.
Meeting prevailing wage & apprenticeship requirements qualifies for the higher deduction rate (approximately 5x the base rate).
Climate controlled buildings include HVAC systems and insulation.
Building is 40,000+ square feet
Minimum square footage requirement for 179D eligibility.
Get the Most Out of Your 179D Deduction
The 179D deduction can reach up to $5.81 per sq ft, but capturing the full benefit requires a certified energy study. Our team will analyze your building systems and manage the documentation from start to finish.
This is an estimate only. Actual deduction amounts require a Section 179D certification study to verify energy efficiency compliance.
Learn More
The CSSI Advantage: Maximizing Your Energy Efficiency ROI
Eligibility
Section 179D isn’t just for new construction. Commercial building owners, real estate developers, and design professionals working on government-owned properties may qualify for significant per-square-foot deductions. If your building has been constructed or renovated with energy-efficient improvements to lighting, HVAC, or the building envelope since 2006, you likely qualify.
Immediate Tax Savings
Our engineering analysis identifies all qualifying energy-efficient improvements, typically generating up to $5.81 per square foot in federal tax deductions that directly reduce your taxable income.
Capture Past & Future Credits
Claim deductions retroactively for qualifying projects completed in prior open tax years through amended returns. Act soon as 179D is sunsetting in June, so projects placed in service before the deadline may still qualify for new claims.
Complete Study Documentation
We deliver a comprehensive report with all required energy modeling, system certifications, and IRS documentation, providing audit-ready substantiation that protects your deductions.
Industry-Leading Track Record
With specialized 179D teams across commercial, multifamily, and government projects, CSSI has secured hundreds of millions in energy deductions for clients without ever triggering an IRS audit.
Start Reducing Your Tax Burden Now
Discover the hidden tax benefits for your property or business with our no-cost preliminary analysis. Our experts will evaluate your eligibility and estimate your potential savings with no obligation.
Frequently Asked Questions
How does the 179D deduction work?
The 179D deduction is a federal tax incentive designed to encourage energy efficiency in commercial buildings. It allows building owners or designers of government buildings to claim a tax deduction of up to $5.81 per square foot for qualifying improvements to lighting, HVAC, or building envelope systems. To qualify, the property must meet specific energy reduction standards as defined by IRS guidelines.
The process begins with a certified engineering analysis of the building’s energy systems. If the improvements meet or exceed the required efficiency levels, the property owner can claim the deduction for the tax year the project was placed in service. This deduction directly reduces taxable income and improves cash flow.
CSSI helps property owners and designers determine 179D eligibility, conduct the required third-party certification, and file the proper documentation. When combined with a cost segregation study, 179D can create even greater tax savings by accelerating depreciation and reducing overall tax burden.
Does the 179d deduction reduce basis?
Yes, the 179D deduction does reduce the basis of the property. When a commercial building owner claims the 179D energy efficiency deduction, the amount deducted is subtracted from the depreciable basis of the building. This means the cost basis used for calculating depreciation in future years will be adjusted downward by the amount of the 179D deduction claimed.
For example, if you install qualifying energy-efficient systems like HVAC, lighting, or building envelope upgrades and claim a $100,000 deduction under Section 179D, your building’s depreciable basis is reduced by that same amount. This adjustment helps prevent double-dipping on tax benefits while still offering a valuable incentive to invest in energy-efficient improvements.
CSSI helps building owners navigate both cost segregation and 179D opportunities. With a strategic approach, you can maximize tax savings while maintaining compliance with IRS requirements. When managed properly, even with the basis reduction, the 179D deduction can lead to significant upfront tax benefits that outweigh the adjustment.
How long has the 179D deduction been available?
How long has the 179d deduction been available?
The 179D deduction was first enacted in 2005 and has been extended and modified several times. It was made permanent in 2020 and expanded in 2022 under the Inflation Reduction Act.
What documentation is needed to claim the 179D deduction?
What documentation is needed to claim the 179D deduction?
You’ll need certification from a qualified individual (like a licensed engineer or contractor) that the required energy savings have been achieved. This typically involves energy modeling software to demonstrate the energy cost reductions.
Can the 179D deduction be claimed for retrofits or renovations?
Can the 179d deduction be claimed for retrofits or renovations?
Yes, the deduction can be claimed for both new construction and renovations of existing buildings.
Who can claim the 179D deduction?
Who can claim the 179d deduction?
The deduction can be claimed by building owners, tenants, or designers of government-owned buildings.
How much is the 179D deduction worth?
The deduction can be up to $5.81 per square foot for buildings that achieve a 50% reduction in energy costs compared to a reference building. Partial deductions of $0.60 per square foot are available for each qualifying system.
What energy systems can qualify for the 179D deduction?
The deduction applies to three types of systems:
- Interior lighting
- Building envelope (roof, walls, windows, doors)
- Heating, cooling, ventilation, and hot water systems
What types of buildings qualify for the 179D deduction?
Qualifying buildings include commercial buildings and multi-family residential buildings four stories or higher. This includes offices, retail spaces, industrial buildings, warehouses, and apartment complexes.
What is the 179D tax deduction?
The 179D tax deduction is an incentive for designing energy-efficient commercial buildings. Building owners can claim a tax deduction for installing qualifying energy-efficient systems.
