A door’s depreciation life is 27.5 years in a residential rental property and 39 years in a nonresidential building, because the IRS treats a permanently installed door as a structural component of the building it belongs to. Several exceptions shorten that timeline sharply: a replacement interior door in a commercial building can drop to 15 years as qualified improvement property, specialized doors tied to a business process can fall into 5- or 7-year classes, and inexpensive doors can often be deducted in full the year you buy them.
Why the Building’s Life Controls the Door’s Life
Treasury Regulation 1.48-1(e)(2) lists doors alongside walls, floors, ceilings, windows, plumbing, wiring, and HVAC as structural components of a building.1GovInfo. 26 CFR 1.48-1 – Definition of Section 38 Property Because a structural component rides with the building, it doesn’t get its own class life. Exterior entrance doors, interior passage doors, and any other door permanently affixed to the structure fall under this rule.
One boundary worth stating up front: depreciation applies only to property used in a trade, business, or income-producing activity. A door on your personal home is not depreciable.2Internal Revenue Service. Topic No. 704 – Depreciation
27.5 Years for Residential Rentals
A building counts as residential rental property when 80 percent or more of its gross rental income comes from dwelling units.3Office of the Law Revision Counsel. 26 USC 168 – Accelerated Cost Recovery System Apartments, duplexes, and single-family rentals all qualify. Doors in these properties depreciate over 27.5 years using the straight-line method and a mid-month convention, meaning a door placed in service in a given month is treated as installed at the midpoint of that month.4Internal Revenue Service. Depreciation and Recapture 4
39 Years for Commercial Buildings
Offices, warehouses, retail stores, and other nonresidential structures carry a 39-year recovery period.3Office of the Law Revision Counsel. 26 USC 168 – Accelerated Cost Recovery System A door installed as part of the original construction depreciates over that full span, straight-line, mid-month. The math is simple; the timeline is long enough that the exceptions below are usually where the real deductions live.
15 Years for Replacement Interior Doors in Commercial Buildings
When you replace or add interior doors in a nonresidential building that’s already in service, those doors can qualify as qualified improvement property (QIP), which carries a 15-year recovery period instead of 39.3Office of the Law Revision Counsel. 26 USC 168 – Accelerated Cost Recovery System
QIP covers any improvement to the interior of a nonresidential building made after the building was first placed in service. The statute excludes three categories: building enlargements, elevators and escalators, and changes to the building’s internal structural framework (load-bearing walls, columns, and beams).3Office of the Law Revision Counsel. 26 USC 168 – Accelerated Cost Recovery System Replacing interior doors doesn’t fall into any of those, so it generally qualifies.
The timing distinction matters. A door installed with the original construction is part of the 39-year building. A door placed in service later, as a replacement or addition, is QIP at 15 years. Owners frequently miss this and sweep replacement doors into the building’s remaining schedule, leaving faster deductions unclaimed.
Bonus Depreciation on QIP
QIP also qualifies for bonus depreciation. Under the One Big Beautiful Bill Act signed in 2025, 100 percent first-year bonus depreciation was permanently restored for qualifying property acquired and placed in service after January 19, 2025.5Internal Revenue Service. Notice 2026-11 – Interim Guidance on Bonus Depreciation Rules A qualifying interior door replacement in a commercial building placed in service in 2026 can be fully deducted in year one. The earlier phase-down schedule no longer applies.
5 or 7 Years for Specialized Doors
Some doors serve a specific business function rather than sitting in the building envelope. A vault door in a bank, a blast-resistant door in a munitions facility, or a heavy-duty cold-storage door in a freezer warehouse behaves more like specialized equipment than a structural component. A cost segregation study can reclassify these into 5-year or 7-year personal property classes depending on the industry and the specific asset.
The IRS Cost Segregation Audit Technique Guide acknowledges that certain door types, including overhead doors, revolving doors, and mall entrance systems, receive separate treatment from the building structure. Matching the door to the correct asset class under the Revenue Procedure guidelines is detailed work, and it’s usually where professional help pays for itself.
One less common situation: an exterior door that forms part of a larger land improvement, such as a gate within a perimeter fence, can fall into the 15-year land improvement class rather than the building’s recovery period.
When You Can Skip Depreciation Entirely
Not every door has to be depreciated at all. Three provisions let you deduct the cost in the year you pay it.
De Minimis Safe Harbor
If the cost of a door falls below the de minimis threshold, you can elect to expense it in the year of purchase. The ceiling is $5,000 per item or invoice if your business has an applicable financial statement (audited financials), or $2,500 per item if it doesn’t. A standard interior door with installation often comes in under $2,500, making the election useful for smaller replacements. It’s an annual election made by attaching a statement to that year’s return, and it applies to all qualifying expenditures for the year.6Internal Revenue Service. Tangible Property Final Regulations
Section 179
Section 179 lets a business deduct the full purchase price of qualifying property in the year it’s placed in service. For 2026, the maximum deduction is approximately $2,560,000, with a phase-out beginning when total qualifying purchases exceed roughly $4,090,000. The deduction also cannot exceed your taxable business income for the year. Section 179 covers tangible personal property and certain improvements to nonresidential buildings, including QIP, so a qualifying commercial door replacement can be fully deducted this way as well.
Repairs, Not Improvements
If you’re fixing a door rather than replacing it, no depreciation may be needed at all. The IRS separates repairs (deductible in the year paid) from improvements (capitalized).6Internal Revenue Service. Tangible Property Final Regulations An expenditure is an improvement if it creates a betterment, restores the property, or adapts it to a new use. Replacing hinges, fixing a closer mechanism, or repainting a door is routine maintenance. Ripping out a standard door and installing a fire-rated security door that materially upgrades the building is more likely an improvement to capitalize. A routine maintenance safe harbor also treats recurring work as a deductible repair if you reasonably expect to perform the same activity more than once during the asset’s class life, which sweeps in virtually any recurring door maintenance on a 39-year building.
Quick Reference by Scenario
- Standard door in a residential rental: 27.5 years, straight-line, mid-month convention.
- Standard door in a commercial building at original construction: 39 years, straight-line, mid-month convention.
- Replacement interior door in a commercial building after it’s in service: 15 years as QIP, eligible for 100 percent bonus depreciation if acquired and placed in service after January 19, 2025.
- Specialized door tied to a business process (vault, cold storage, overhead): potentially 5 or 7 years as personal property, typically identified through a cost segregation study.
- Low-cost door under the de minimis threshold: fully deductible in the year of purchase ($2,500 without audited financials, $5,000 with them).
- Door repair rather than replacement: deductible as a current expense, no depreciation required.
- Door on your personal home: not depreciable.