Section 179D Tax Deductions for Building Owners & Design Firms
Identify valuable tax deductions from qualifying energy-efficient commercial buildings, retrofits, and tax-exempt projects.
Tributan helps commercial building owners, architects, engineers, and design-build firms identify potential 179D opportunities and manage the engineering, energy modeling, certification, and allocation process.
Choose Your Path to Review Eligibility
Commercial Building Owners
Evaluate owned commercial properties, new construction, or major renovations.A/E/C Design Firms
Screen your portfolio of government and tax-exempt building projects.Existing Building & Retrofit Owners
Evaluate recent HVAC, lighting, hot water, or envelope upgrades.However, qualifying projects that began construction on or before this deadline may still be eligible for the deduction.
This creates an opportunity for building owners and design firms to review current and historical project portfolios for previously unclaimed deductions.
If your company owns, designed, or renovated commercial or tax-exempt properties, Tributan can review your project portfolio to identify which assets warrant a formal 179D analysis.
Have Projects That May Still Qualify?
Building owners and design firms may still have opportunities within current and historical project portfolios. If your company owns, designed, or renovated commercial or tax-exempt properties, Tributan can review those projects to identify which ones may warrant a formal 179D analysis.
A/E/C Portfolio Review
Evaluate completed public-sector and tax-exempt projects to determine potential eligibility for allocated designer deductions.
Building-Owner Historical Construction
Review commercial buildings and major improvements placed in service in prior years.
Existing-Building Retrofits
Evaluate recent HVAC, lighting, hot water, or building envelope upgrades under applicable modeling or retrofit pathways.
What Is Section 179D?
Section 179D of the Internal Revenue Code provides a tax deduction for qualifying energy-efficient commercial building property.
The deduction generally applies to energy-saving improvements made to:
- Interior Lighting Systems
- HVAC & Hot Water Systems
- Building Envelope (windows, doors, roofing, insulation)
Who May Claim the Deduction?
Section 179D opportunities generally fall into two categories: deductions claimed by qualifying commercial building owners and allocated deductions for eligible designers of qualifying tax-exempt building projects.
How Much Could Your 179D Deduction Be?
Section 179D deductions are calculated on a per-square-foot basis, with higher deduction amounts available when specific statutory criteria are met.
The applicable deduction depends on the tax year, qualifying energy performance, building square footage, prior 179D deductions, and eligibility for the increased deduction amount.
Illustrative Example
A qualifying 100,000-square-foot facility could potentially generate a substantial six-figure deduction depending on its applicable rate. Actual deductions depend on project-specific qualification requirements, energy performance, and applicable statutory limitations.
Applicable Taxable Year Reference Rates (Illustrative Guidelines)
| Taxable Year | Base Rate Range (Per Sq. Ft.) | Increased Deduction Rate Range (Per Sq. Ft.) |
|---|---|---|
| 2023 | $0.54 – $1.07 | $2.68 – $5.36 |
| 2024 | $0.57 – $1.13 | $2.83 – $5.65 |
| 2025 | $0.58 – $1.16 | $2.90 – $5.81 |
| 2026 | $0.59 – $1.19 | $2.97 – $5.94 |
2026 increased deduction rates can reach up to $5.94 per sq. ft. for qualifying projects.
Higher deduction amounts may be available when applicable Prevailing Wage and Apprenticeship (PWA) requirements are satisfied or another statutory exception applies (such as construction beginning prior to January 29, 2023). Deduction amounts are indexed annually by the IRS and depend on the applicable tax year and qualifying energy performance.
Existing Building & Retrofit Opportunities
Section 179D isn’t limited to new ground-up construction. Certain existing buildings that undergo qualifying energy-efficiency retrofits may also be eligible.
Depending on the project scope and historical documentation, qualification may be established through:
Traditional Energy-Modeling Pathway
Evaluating calculated energy savings against applicable reference standards.
Alternative Retrofit Pathway
Certain existing buildings may qualify through a qualified retrofit plan based on measured reductions in energy use intensity (EUI), subject to specific building-age (generally placed in service at least 5 years prior), certification, baseline measurement, and timing requirements.
Who May Qualify?
Commercial building types that may qualify include:
- Office Buildings & Corporate Campuses
- Industrial & Manufacturing Facilities
- Warehouses & Distribution Centers
- Hotels & Hospitality Properties
- Retail Outlets & Shopping Centers
- Commercial Parking Structures
- Qualifying Multi-Family Residential Buildings (4+ stories)
Designers responsible for specifying energy-efficient systems on tax-exempt properties may be eligible for an allocated deduction. Qualifying entity types include:
- Federal, State, and Local Government Buildings
- Public K-12 Schools & Higher Education Campuses
- Public Hospitals & Healthcare Facilities
- Private Nonprofits & Houses of Worship
- Tribal Government Facilities
The 179D Process
Initial Eligibility Review
Review project scope, dates, location, building size, and other basic eligibility factors.
Document Collection
Collect available plans, utility data, equipment specifications, and project information.
Energy Modeling & Engineering Analysis
Evaluate the project's energy performance using qualified energy-modeling software.
Site Inspection & Certification
Verify the installed energy-efficient systems and complete the required certification.
Allocation Letter Management (A/E/C Only)
Assist with the allocation process for eligible designer deductions.
Substantiation Package
Provide the supporting engineering analysis, certification, and documentation for the deduction.
CPA Coordination
Provide the client's CPA or tax professional with the information needed to support reporting of the deduction.
Initial Eligibility Review
Review project scope, dates, location, building size, and other basic eligibility factors.
Document Collection
Collect available plans, utility data, equipment specifications, and project information.
Energy Modeling & Engineering Analysis
Evaluate the project's energy performance using qualified energy-modeling software.
Site Inspection & Certification
Verify the installed energy-efficient systems and complete the required certification.
Allocation Letter Management (A/E/C Only)
Assist with the allocation process for eligible designer deductions.
Substantiation Package
Provide the supporting engineering analysis, certification, and documentation for the deduction.
CPA Coordination
Provide the client's CPA or tax professional with the information needed to support reporting of the deduction.
Built for IRS Substantiation
Section 179D requires rigorous engineering, physical inspection, and modeling standards. Tributan delivers study packages structured to support the deduction.
Qualified Professional Verification
Studies are verified and certified by qualified Professional Engineers (PE) or licensed professionals meeting statutory independence and qualification requirements.
Compliant Software
Energy modeling is conducted using software meeting IRS and Department of Energy requirements.
Structured Substantiation
Reports include complete software outputs, baseline comparisons, inspection documentation, and calculation schedules.
Post-Engagement Support
If questions arise during an IRS or state review, available support will be provided in accordance with the terms of the engagement agreement.
Evaluating Combined Tax Strategies
Depending on the property, Section 179D may also be evaluated alongside a Cost Segregation Study.
Section 179D
Focuses on qualifying energy-efficient lighting, HVAC, and building envelope property.
Cost Segregation
Analyzes eligible building components that may qualify for shorter depreciation recovery periods (e.g., specialized electrical, site improvements, interior finishes).
Frequently Asked Questions
Section 179D was terminated for property that begins construction after June 30, 2026. Projects that began construction on or before the deadline may still qualify, subject to normal Section 179D requirements.
Potentially. Depending on the taxpayer and specific facts, certain building owners may be able to address a missed historical deduction through an accounting method change using IRS Form 3115, rather than amending a prior-year return.
Other situations—such as allocated designer deductions for A/E/C firms—may require a different filing approach. Tributan coordinates with your CPA or tax professional to determine the appropriate treatment.
Potentially. Architects, engineers, design-build contractors, MEP consultants, and other firms may qualify when they meet the statutory requirements to be treated as an eligible designer responsible for creating the technical specifications for qualifying systems on tax-exempt property.
An Allocation Letter documents the tax-exempt building owner’s allocation of the Section 179D deduction to an eligible designer. Tributan assists with the allocation process and supporting documentation.
Potentially. Additional qualifying energy-efficient improvements made in subsequent years may create another Section 179D opportunity, subject to applicable prior-deduction cap rules and updated reference standards.
Find Out Which of Your Projects May Qualify
Submit your project details or project list for an initial eligibility review. We'll help identify which projects may warrant a full Section 179D analysis.
Have Multiple Projects?
Have a spreadsheet or portfolio overview? Send it to us and we'll help identify which projects may warrant further Section 179D review.