Earn up to $5.65 per square foot in deductions (179D) or $5,000 per unit in credits (45L) for energy-efficient buildings — commercial and residential.
Two federal tax programs reward energy-efficient construction. §179D gives commercial building owners deductions up to $5.65 per square foot for efficient HVAC, lighting, building envelope, and hot water systems. §45L gives residential developers credits up to $5,000 per unit for properties meeting ENERGY STAR or ZERH standards. The key difference? §179D is a deduction (reduces taxable income), §45L is a credit (reduces tax dollar-for-dollar). Both programs are permanent, and both require third-party certification to claim the benefits.
Two powerful federal programs — one for commercial buildings, one for residential properties
Energy Efficiency Deduction
Energy Efficient Home Credit
Designers & Engineers: You can claim §179D deductions for government and tax-exempt buildings you design — even if you don't own the property.
Get a free benefits analysis to see if your properties qualify for 179D, 45L, or both.
Claiming energy tax incentives isn’t just about checking boxes — it requires deep technical expertise, IRS-approved certification, and strategic coordination across complex building systems. After 30,000+ studies and two decades in the field, we’ve learned what separates exceptional results from missed opportunities.
We handle the entire certification process — from energy modeling and building inspections to IRS Form submission. Our in-house engineers ensure every qualifying system is documented and every available dollar is claimed.
Most firms specialize in one program. We master both — strategically coordinating 179D and 45L across your entire portfolio to capture every available dollar whether you’re developing commercial, residential, or mixed-use properties.
Our licensed engineers conduct on-site inspections and comprehensive energy modeling — not desktop software analysis. This engineering-led approach uncovers qualifying systems and components that generic consultants miss entirely.
With both programs now time-limited, we help integrate energy efficiency into your tax strategy — coordinating with cost segregation, working with your CPA, and positioning you to capture available benefits before they phase out.
Both programs cover a wide range of property types and ownership structures. If you’ve constructed, renovated, or acquired energy-efficient buildings, you likely qualify for significant tax benefits — even retroactively.
From initial analysis to IRS filing and lifetime audit support, we manage every step of your energy incentive claim. Our streamlined process ensures maximum benefits with zero administrative burden on your team.
We review your property portfolio, construction plans, or completed projects to identify all eligible buildings and estimate potential tax benefits under both 179D and 45L programs.
Our licensed engineers conduct comprehensive energy modeling and building inspections, analyzing HVAC systems, lighting, building envelope, hot water systems, and overall energy performance against IRS standards.
As IRS-approved certifiers, we provide the required third-party certification for both programs, ensuring compliance with all technical requirements and documentation standards.
We prepare all necessary tax documentation, including IRS forms, engineering reports, and supporting schedules. We work directly with your CPA or tax advisor to ensure seamless filing.
If the IRS ever questions your energy incentive claims, we provide complete audit support at no additional cost. Our documentation withstands scrutiny, and we stand behind every certification.
4-8 weeks from engagement to completed certification
Expedited processing for time-sensitive projects
Schedule a free consultation to discuss your properties and receive a preliminary benefit analysis.
Section 179D is a tax deduction (up to $5.65/SF) for energy-efficient commercial buildings. Section 45L is a tax credit(up to $5,000/unit) for energy-efficient residential properties. 179D reduces taxable income; 45L reduces tax dollar-for-dollar. Both are permanent and require third-party certification.
179D: Commercial buildings including offices, retail, warehouses, hotels, healthcare facilities, and multifamily (4+ stories).
45L: Residential properties including single-family homes, townhomes, condos, apartments, and senior housing.
179D: Building owners, tenants who made improvements, or designers (architects/engineers) for government buildings.
45L: Developers, builders, and contractors who constructed the property and then sold or leased it.
179D: 25%+ energy reduction vs. ASHRAE 90.1 standards (50%+ for maximum deduction).
45L: ENERGY STAR certification ($2,500/unit) or DOE ZERH certification ($5,000/unit) for properties completed 2023 or later.
Yes. Both programs require IRS-approved certification from qualified professionals. CSA Partners is an IRS-approved certifier with licensed engineers who handle the entire process in-house.
Yes. 179D can be claimed for buildings placed in service after 2005. 45L is retroactive for three years or any open tax year. Many property owners have unclaimed benefits from past projects.
Typically 4-8 weeks from engagement to completed certification. This includes energy modeling, building analysis, certification documentation, and filing preparation. Rush services are available when needed.
CSA Partners provides 100% no-cost lifetime audit support. Our engineering-based methodology and comprehensive documentation are designed to withstand IRS scrutiny. We’ve never had a certification challenged or disallowed.
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