Written by Brown, Edwards, & Company, LLP, recognized as a Top 50 Construction Accounting firm for seven consecutive years, with over 30 years of construction industry expertise and eleven CCIFPs on our construction practice team. The One Big Beautiful Bill Act signals a significant shift in energy-efficient tax incentives and sets an end date for the Section 179D Energy-Efficient Commercial Buildings Deduction. Construction projects beginning after June 30, 2026, will no longer qualify for this tax benefit. In our three decades of serving construction companies, few changes have affected the industry as significantly as the termination of this deduction.
Before diving into the implications of its termination, it is essential to understand the current guidelines to fully appreciate the impact of the sunsetting deduction. For 2025, the 179D deduction offers up to $5.81 per square foot for qualifying energy-efficient commercial building improvements when projects meet prevailing wage and apprenticeship requirements. The deduction is capped at $1.16 per square foot for projects that do not meet these labor standards.
The deduction applies to energy-efficient property installed as part of the systems noted below.
To qualify, projects must achieve at least 25% energy savings compared to ASHRAE Standard 90.1 baseline requirements, with the deduction amount increasing based on the level of energy efficiency achieved. Projects can be new construction or building upgrades with an eligible energy-efficient property in service. Two evaluation methodologies are available. One measures the modeled energy and power cost savings %, while the other measures site energy use intensity savings.
Construction companies face a compressed timeline. To qualify for the 179D deduction, construction must begin before June 30, 2026. This creates several immediate challenges and opportunities:
Project Planning Acceleration
Companies with energy-efficient projects in their pipeline should evaluate projects to determine if planning and design phases can be accelerated to meet the deadline. This expedited timeline may strain design teams and require earlier commitment to project specifications than initially planned.
Cash Flow Considerations
Commercial building owners, architects, engineers, and contractors can still claim up to $5.81 per square foot for energy-saving improvements through the deadline. For passthrough entities (S Corporations and Partnerships), you will want to understand how the deduction affects your basis and deductibility.
Shift in Project Economics
The loss of the 179D incentive will affect the financial modeling for energy-efficient construction projects. Projects that were economically viable due to the tax deduction may require reassessment after the provision sunsets. We recommend that construction companies proactively address these three areas:
Competitive Landscape Changes
Design professionals who rely on 179D to demonstrate value and reduce taxable income must consider the ramifications of the short-term demand and the long-term impact.
Client Education and Relationship Management
Construction firms must proactively educate clients about this deadline. Many building owners may be unaware of the deadline and the potential tax benefits at stake.
Commercial Construction
The commercial sector will see the most dramatic impact, as 179D has been a significant driver of energy-efficient upgrades and new construction. Office buildings, retail spaces, and industrial facilities planning energy-efficient improvements may need to expedite their timelines.
Government and Non-Profit Projects
The Section 179D deduction can be allocated to designers (architects, engineers, and design-build contractors) responsible for the design components of government-owned and other tax-exempt, energy-efficient buildings. The loss of this allocation opportunity will particularly impact firms specializing in public sector work.
Multifamily Housing
Large multifamily projects (four stories or higher) that qualify for 179D must begin construction before the deadline to capture these benefits.
Immediate Steps (Next 6 Months)
Project Pipeline Review: Conduct a comprehensive review of all planned projects to identify those that could qualify for 179D benefits
Client Communication: Proactively reach out to clients with pending projects to discuss the deadline, available resources, and potential benefits
Accelerated Design Phases: Consider the possibility of fast-tracking design development for qualifying projects
Medium-Term Planning (6-22 Months)
Resource Allocation: Prepare for potential increased demand as we approach the June 2026 deadline
Partnership Development: Strengthen relationships with experienced energy consultants and certification professionals who can expedite the 179D qualification process
Alternative Incentive Strategy: Begin exploring state and local energy efficiency incentives that may partially offset the loss of federal benefits
Long-Term Strategy (Post-2026)
Strategy Adaptation: Develop strategies for promoting energy-efficient construction without federal tax incentives
Value Focus: Refocus energy efficiency messaging around operational savings, environmental benefits, and potential future incentives
Market Positioning: Consider how the loss of 179D might create opportunities in renovation and retrofit markets
The importance of proper documentation for projects that qualify before the deadline cannot be overemphasized. Building owners should plan carefully, document all related construction information, and keep appropriate records about Section 179D tax positions.
Key documentation requirements include:
The termination of the 179D tax deduction marks the end of two decades of federal incentives for energy-efficient commercial construction. While this change presents challenges, construction companies have a 22-month window of opportunity to capture remaining benefits.
For more information about the 179D qualification or construction tax planning strategies, contact Brown, Edwards, & Company, LLP at [contact information]. Our construction practice team brings over 30 years of industry experience and expertise in navigating complex tax incentives and regulatory changes.
The deadline is firm: June 30, 2026. The time to act is now.
Brown Edwards. (2025). Claude.ai (Sonnet 4). https://claude.ai/