Section 179 Commercial Roofing 2026: OBBBA Doubles the Limit

What Did the OBBBA Change About Section 179?

The One Big Beautiful Bill Act (Pub. L. 119-21, July 4, 2025) raised the Section 179 deduction limit to $2,560,000 for 2026, up from $1,220,000 in 2024. A commercial roof restoration placed in service by December 31, 2026 qualifies for full year-one expensing. These limits are now permanent and indexed for inflation going forward.

Before the OBBBA, the 2024 limit was $1,220,000, with a phase-out beginning when total qualifying property placed in service exceeded $3,050,000 in the tax year (Rev. Proc. 2023-34).

Three things changed:

The deduction limit nearly doubled. For 2025 it jumped to $2,500,000. For 2026, inflation adjustments bring it to $2,560,000 (Rev. Proc. 2025-32).

The phase-out threshold increased proportionally. In 2026, the deduction begins to phase out when total qualifying property placed in service exceeds $4,090,000. The deduction phases out completely at $6,650,000. For most individual building owners, the phase-out won't apply.

The limits are now permanent. Under the old law, limits were set to phase down. The OBBBA made the enhanced limits permanent and indexed them to inflation going forward.

For the typical building owner with a single large restoration project: if the project is under $2,560,000 and your total qualifying property for the year is under $4,090,000, you can expense the entire project in year one.

Does a Silicone Roof Restoration Qualify for Section 179?

Yes, but how the project is characterized matters — and that's a CPA decision, not a roofing contractor decision.

The IRS Form 4562 Instructions (2025) explicitly name "Roofs" as qualifying property for Section 179 expensing under nonresidential real property improvements, per IRC §179(e). This is stated directly, not by inference.

The question is whether the specific work constitutes a capital improvement or a repair.

Section 179 only applies to capitalized expenditures. If your project is treated as a routine repair under IRC §162, it's deductible in full in the current year without any Section 179 election. That's not necessarily worse; a full current deduction under §162 has no dollar limit. But it's a different code section.

The rule that governs this is Treasury Regulation §1.263(a)-3, the BAR test:

• Betterment: Did the work materially improve the building's capacity, efficiency, or condition?
• Adaptation: Did it convert the building to a different use?
• Restoration: Did it return the property to working condition after significant deterioration, or replace a major component?

A full-surface spray-applied silicone restoration over a deteriorated EPDM or TPO membrane — sealing failed seams, addressing moisture infiltration, extending the roof's service life by 20+ years — typically meets the Restoration prong. The work addresses significant deterioration and restores the roofing system as a whole.

A routine preventive re-coat of a silicone membrane still in serviceable condition may fall under the Routine Maintenance Safe Harbor (Treas. Reg. §1.263(a)-3(i)) and qualify as a repair.

How we scope and describe the project matters. "Restoration" and "maintenance" aren't just marketing language; they carry tax implications. Before signing a restoration contract on any project where Section 179 is on the table, have your CPA review the scope description.

Why Can't You Use Bonus Depreciation on a Commercial Roof?

Bonus depreciation does not apply to commercial roofs because roofs are not Qualified Improvement Property. IRC §168(e)(6) covers only interior improvements to nonresidential buildings. Roofs are exterior structural components with a 39-year class life, and bonus depreciation requires a 20-year or shorter class life. Section 179 is the only accelerated depreciation tool available for a commercial roof restoration.

Every assessment I do on a project above $300,000, the same question comes up from whoever handles the finances: "Can we use 100% bonus depreciation instead of Section 179?"

The answer is no. The reason is worth knowing.

The OBBBA restored 100% bonus depreciation for qualifying property acquired and placed in service after January 19, 2025 (IRS Notice 2026-11). A significant change. But bonus depreciation applies to Qualified Improvement Property (QIP) and to property with a 20-year or shorter MACRS class life.

Roofs are not QIP. Under IRC §168(e)(6), QIP covers only improvements to the *interior* of a nonresidential building. Roofs are exterior structural components, which is why they're named separately under IRC §179(e) rather than folded into QIP. This is explicit in the statute, not a gray area.

A commercial roof carries a 39-year class life under MACRS. Bonus depreciation does not apply to 39-year property.

If you don't elect Section 179 on a commercial roof, the fallback is 39-year straight-line depreciation — roughly $12,820 per year on a $500,000 project, generating about $2,692 in annual federal tax savings at a 21% effective rate. Section 179 converts that same $500,000 into $105,000 in year one.

What Is Section 179D, and Why Does the June 30 Deadline Matter?

Section 179D is a separate deduction from Section 179. For a qualifying silicone cool-roof coating, the 2026 deduction rate ranges from $0.59 to $5.94 per square foot depending on prevailing wage compliance (Rev. Proc. 2025-32). On a 100,000 sq ft building, that's $59,000 to $594,000 in additional deductions stacked on top of Section 179 — but only for projects where construction began on or before June 30, 2026. After that date, the OBBBA eliminated 179D for new projects entirely.

Section 179D applies to improvements to a commercial building's envelope (roofing, walls, windows, insulation), interior lighting, or HVAC systems that demonstrably reduce the building's total energy costs. For a spray-applied silicone cool-roof coating with high solar reflectance, the building envelope is the applicable system.

The 2026 deduction rates, per Rev. Proc. 2025-32:

At a 21% effective rate, the range runs from $12,390 to $124,740 in additional federal tax savings on a 100,000 sq ft building.

The problem: The OBBBA terminated Section 179D for projects where construction begins after June 30, 2026. It is not a phase-down. It is an end date.

First, the deadline is "construction begins," not "project is placed in service." IRS applies a physical work of significant nature test — actual roof work underway, not just contract signing or materials procurement. Confirm the construction-start date with your tax advisor before assuming you've met the threshold.

Second, claiming 179D requires more than buying an ENERGY STAR-certified product. A third-party certified energy model must demonstrate at least 25% whole-building energy cost reduction against ASHRAE 90.1-2007. The coating itself doesn't create the certification. An independent energy modeler runs the building's full energy profile, and that process takes weeks.

If you want 179D on a 2026 roof project, the assessment, scope, modeling engagement, and construction mobilization all need to happen before June 30. That's a tight sequence.

What Does This Look Like in Real Dollars?

A specific scenario, with every figure sourced.

The project:

• 100,000 sq ft commercial warehouse
• Spray-applied silicone restoration over existing EPDM membrane
• Project cost: $500,000
• Tax year: 2026, calendar year taxpayer
• Entity: Profitable S-corporation, 21% effective federal rate
• Predicate: CPA has characterized the project as a capital improvement under Treas. Reg. §1.263(a)-3

Section 179 outcome:

The 2026 limit is $2,560,000 (Rev. Proc. 2025-32). The project cost of $500,000 is well under that limit. The phase-out threshold of $4,090,000 doesn't apply. The full $500,000 qualifies.

Section 179 deduction: $500,000 in year one. Federal tax savings: $500,000 × 21% = $105,000 in year one.

Without Section 179: $500,000 over 39 years = $12,820/year in deductions, about $2,692/year in tax savings. Section 179 moves all $105,000 into year one.

If Section 179D also applies (construction began on or before June 30, 2026):

Conservative — no PWA compliance, 25% energy savings threshold met: $0.59/sq ft × 100,000 sq ft = $59,000 additional deduction. Additional tax savings: $12,390.

PWA-compliant, base rate: $2.97/sq ft × 100,000 sq ft = $297,000 additional deduction. Additional tax savings: $62,370.

Combined year-one outcome (Section 179 + 179D at base PWA rate):

Total deductions: $797,000. Total federal tax savings at 21%: $167,370 in year one.

Required caveats: these numbers use a 21% effective rate for illustration. Section 179 cannot exceed aggregate taxable income from the active conduct of a trade or business — excess carries forward. The 179D figures require third-party energy certification. State taxes are excluded and state conformity to OBBBA varies significantly. Recapture under IRC §1245 applies if the building is sold before the 39-year recovery period ends. Run this against your actual situation with a CPA.

What Should Facility Managers Do Before December 31, 2026?

Two deadlines control the 2026 Section 179 window for commercial roofing. Construction must begin by June 30 to preserve Section 179D eligibility. The roof must be placed in service by December 31 to claim the Section 179 deduction at all. If you miss December 31, there is no Section 179 deduction for 2026, regardless of when the project started.

Deadline 1 — June 30, 2026: Section 179D.

Construction must have begun on or before this date to preserve 179D eligibility. If your project has not mobilized yet and this date has passed, 179D is not available. There is no exception.

Deadline 2 — December 31, 2026: Section 179.

The project must be placed in service by this date, meaning the work is complete and the roof is functional. Signing a contract before year-end doesn't qualify. Ordering materials doesn't qualify. The roof needs to be done.

For large commercial projects, this matters practically. A silicone spray restoration on a 200,000 sq ft warehouse takes 2 to 4 weeks of crew time, depending on substrate condition, weather access, and crew size. If a facility director calls us in August, there's time to assess, scope, and schedule. If they call in November, we're having an honest conversation about whether December 31 is achievable.

Steps to take now:

1. Schedule an infrared moisture survey and assessment to confirm restoration eligibility and define the project scope 2. Have your CPA review the scope description before signing any contract, to confirm capital improvement vs. repair characterization 3. If 179D hasn't been ruled out, engage a certified energy modeler immediately — the modeling process takes weeks 4. Confirm state tax conformity with your CPA; many states haven't adopted the OBBBA's enhanced Section 179 limits 5. Set a project start target of no later than September or October for roofs over 100,000 sq ft, to allow contingency time before December 31

What Are the Section 179 Limitations for Commercial Roofing?

Section 179 has real constraints. The most significant for large building owners: the deduction cannot exceed your aggregate taxable income from the active conduct of a trade or business in the current year. If your $500,000 deduction exceeds your business income, the excess carries forward indefinitely, but it doesn't generate a refund in year one (IRC §179(b)(3)).

Tax-exempt entities — nonprofits, government agencies, universities — can't claim Section 179. If your organization has no federal income tax liability, the deduction has no value. This affects a meaningful segment of the large commercial building market; hospitals, universities, and government-leased facilities are common large-roof owners who don't benefit from it.

Tenants in leased buildings typically can't claim Section 179 on roofing work, because the roof is owned by the landlord, not the tenant. Triple-net lease structures have their own complexity; get specific advice about your lease terms.

Two downstream risks are worth knowing before electing Section 179. If you claim it on a roof and later sell the building, the previously deducted amount may be recaptured as ordinary income rather than capital gain under IRC §1245 in the year of sale. For owners who expect to sell within a few years, model the recapture exposure before electing. And many states have not conformed to the OBBBA's enhanced federal limits. Your state may apply the pre-OBBBA caps or its own depreciation schedule. Federal savings don't automatically replicate at the state level.

Finally, IRC §179(e) applies to nonresidential real property only. Residential rental buildings are excluded. Mixed-use buildings may require apportionment.

FAQ

What is the Section 179 deduction limit for commercial roofing in 2026?

$2,560,000 for tax year 2026 (Rev. Proc. 2025-32), up from $1,220,000 in 2024. The phase-out begins at $4,090,000 in total qualifying property placed in service and is complete at $6,650,000. These limits are permanent and indexed for inflation annually under the OBBBA.

Can I claim Section 179 on a spray-applied silicone roof restoration?

Yes, if the project is characterized as a capital improvement under the BAR test (Treas. Reg. §1.263(a)-3). A full-surface restoration on a deteriorated membrane that materially extends the roof's useful life typically qualifies. A routine preventive re-coat on a serviceable membrane may qualify as a repair under §162 instead. Your CPA makes this determination based on the actual project scope.

Why can't I use bonus depreciation on a commercial roof?

Roofs are not Qualified Improvement Property. QIP under IRC §168(e)(6) covers only interior improvements to nonresidential buildings. Roofs are exterior structural components with a 39-year class life. Bonus depreciation requires a 20-year or shorter class life. Section 179 is the only accelerated depreciation tool available for commercial roofing.

What happened to Section 179D under the OBBBA?

The OBBBA eliminated Section 179D for projects where construction begins after June 30, 2026. If your project mobilized before that date and meets the energy-efficiency threshold (25% whole-building energy cost reduction against ASHRAE 90.1-2007, verified by a third-party certified energy model), 179D may still apply.

When does the roof need to be done to claim Section 179 for 2026?

The roof must be placed in service — work complete, roof functional — by December 31, 2026. Signing a contract or ordering materials before year-end is not sufficient. For projects over 100,000 sq ft, target completion by November to leave contingency room.