No, a roof is not qualified improvement property. QIP is limited to work done to the interior of a nonresidential building, and a roof is an exterior structural component. The practical workaround for commercial building owners is Section 179, which lets you deduct the full cost of a new roof in the year it is placed in service, up to $2,560,000 for tax years beginning in 2026.
Why the Statute Excludes a Roof
QIP covers improvements a taxpayer makes to an interior portion of a nonresidential building, placed in service after the building itself was first placed in service.1Legal Information Institute (LII). 26 USC 168(e)(6) – Qualified Improvement Property Three requirements have to line up: the work is inside the building, the building is nonresidential, and the improvement is not part of the original construction.
A roof fails the first requirement. It is exterior, not interior. The statute also excludes any spending that enlarges the building or alters its internal structural framework, which is why building additions, load-bearing walls, and exterior windows are outside QIP for the same reason a roof is.1Legal Information Institute (LII). 26 USC 168(e)(6) – Qualified Improvement Property QIP is aimed at tenant-level interior work: new flooring, updated lighting, reconfigured walls.
Because a roof is not QIP, it is not eligible for bonus depreciation as QIP. That is the practical stakes of the classification, and it is why Section 179 matters here.
Section 179 Expensing for a Commercial Roof
Congress addressed the roof problem separately. The Tax Cuts and Jobs Act expanded Section 179 to allow immediate expensing for certain improvements to nonresidential real property, and the list specifically includes roofs, along with HVAC, fire protection and alarm systems, and security systems.2Internal Revenue Service. Depreciation Expense Helps Business Owners Keep More Money Rather than depreciating the roof over decades, you can elect to deduct the full cost in the tax year the roof is placed in service.3Office of the Law Revision Counsel. 26 USC 179 – Election to Expense Certain Depreciable Business Assets
The One, Big, Beautiful Bill Act, signed on July 4, 2025, more than doubled the Section 179 caps.4Internal Revenue Service. One, Big, Beautiful Bill Provisions – Individuals and Workers For tax years beginning in 2026, the maximum deduction is $2,560,000, based on a $2,500,000 statutory floor adjusted for inflation.3Office of the Law Revision Counsel. 26 USC 179 – Election to Expense Certain Depreciable Business Assets That ceiling is high enough to absorb most commercial roof projects. The deduction phases out dollar-for-dollar once total Section 179 property placed in service during the year exceeds $4,090,000, so a business that puts more than roughly $6.6 million of qualifying property into service in a single year loses the deduction entirely.
The Taxable Income Limitation
Section 179 cannot exceed your total taxable income from all active trades or businesses for the year. If the business generates $400,000 of taxable income and installs a $600,000 roof, only $400,000 can be expensed in the current year. The remaining $200,000 is not lost. It carries forward indefinitely until there is enough business income to absorb it.5eCFR. 26 CFR 1.179-3 – Carryover of Disallowed Deduction
When Roof Work Is a Repair Instead
Not every dollar spent on a roof has to be capitalized. Work that qualifies as a repair is deductible as an ordinary business expense in the year paid, no Section 179 election required. The IRS separates repairs from improvements using three tests: betterment, restoration, and adaptation.6Internal Revenue Service. Tangible Property Final Regulations
- Betterment: the work fixes a pre-existing defect, adds capacity, or materially increases efficiency or output.
- Restoration: the work replaces a major component or substantial structural part, or returns non-functional property to working condition.
- Adaptation: the work converts the property to a new or different use.
Patching a leak, replacing a few damaged shingles, or resealing flashing around a vent usually reads as a repair. Tearing off the entire membrane and installing a new one almost always meets the restoration test, because the membrane is a major component. This distinction is most useful when the taxable-income limitation would blunt a Section 179 election.
The Default: 39-Year Depreciation
When neither expensing nor a repair deduction applies, a new roof on a commercial building falls into the general MACRS class for nonresidential real property: 39 years, straight-line.7Internal Revenue Service. Publication 946 – How To Depreciate Property A $500,000 roof recovered on that schedule produces roughly $12,800 of annual deductions. Slow recovery is exactly why most owners reach for Section 179 when they qualify.
One boundary to check first. Real property trades or businesses that elected out of the Section 163(j) business interest expense limitation must depreciate their nonresidential real property under the Alternative Depreciation System, using a 40-year recovery period, with no bonus depreciation available.8Internal Revenue Service. Questions and Answers About the Limitation on the Deduction for Business Interest Expense If you made that election, confirm with a tax advisor before assuming Section 179 is still available for the roof.
Writing Off the Old Roof
When you replace an entire roof, the old one still has remaining tax basis on the books. Without action, you keep depreciating that phantom asset alongside the new roof. The partial disposition election fixes this by letting you recognize a loss equal to the remaining adjusted basis of the old roof in the year it is removed.9Internal Revenue Service. Examining a Taxpayer Electing a Partial Disposition of a Building
The mechanics: separate the old roof’s original cost into its own single-asset account, apply the depreciation that would have been claimed on it since the building was first placed in service, and deduct the basis that remains. The new roof is then capitalized as a separate asset. The election has to be made on a timely filed return (including extensions) for the year of replacement. If you cannot reasonably substantiate the original cost allocable to the old roof, the IRS can disallow the election, so keep the original purchase allocation or get an engineering estimate.
Recapture When You Sell
The upfront deduction from Section 179 is not permanent tax savings. Real property carrying Section 179 adjustments is treated as Section 1245 property for recapture purposes, meaning gain attributable to the expensed roof amount is taxed as ordinary income rather than at capital-gains rates.10Office of the Law Revision Counsel. 26 USC 1245 – Gain From Dispositions of Certain Depreciable Property Expense a $500,000 roof under Section 179, later sell the building at a gain, and up to $500,000 of that gain can be recharacterized as ordinary income. If a sale is on the horizon, weigh the immediate tax savings against the recapture waiting on the other end.
Reporting on Form 4562
The Section 179 election is reported on Form 4562, Depreciation and Amortization.11Internal Revenue Service. About Form 4562 – Depreciation and Amortization In Part I, describe the property (for example, “roof”) in Column (a), enter the total cost on the appropriate line, and enter the amount you elect to expense in Column (c). Any portion of the cost you choose not to expense is depreciated over 39 years in the lower sections of the same form.12Internal Revenue Service. 2025 Instructions for Form 4562 – Depreciation and Amortization
Attach the completed Form 4562 to the original return for the tax year the roof is placed in service, or to a timely amended return. The election is made per asset. You can expense the full cost, a partial amount, or nothing at all, but changing the elected amount after filing requires an amended return within the statutory deadline.12Internal Revenue Service. 2025 Instructions for Form 4562 – Depreciation and Amortization
Before filing, pull together the date the building was originally placed in service, the completion date of the roofing project, invoices that separate the roof cost from any other work, and the contractor’s name and property address. Repair costs on the same project follow different rules, so keep them itemized separately on the invoice.
Records supporting depreciation deductions have to be kept until the statute of limitations runs on the tax year you dispose of the property.13Internal Revenue Service. Topic No. 305 – Recordkeeping In practice, hold the roofing contract, invoices, Form 4562, and proof of the placed-in-service date for as long as you own the building, plus at least three years after filing the return for the year you sell it.14Internal Revenue Service. How Long Should I Keep Records