Capital Improvements in Real Estate: Rules, Taxes, and Safe Harbors

Capital improvements in real estate are permanent changes that increase a property’s value, extend its useful life, or adapt it to a new use. For tax purposes, the cost of an improvement is not deducted the year you pay it. Instead, you add it to the property’s basis if it’s your home, or depreciate it over a set number of years if the property is a rental or used in a business. A routine repair, by contrast, is deducted (or ignored, for a personal residence) in the year of the expense. Getting the classification right matters: misclassifying an improvement as a repair can trigger a 20% accuracy-related penalty on the resulting tax underpayment.¹

What Counts as a Capital Improvement

Internal Revenue Code Section 263 lays down the general rule that you cannot deduct amounts spent on permanent improvements that increase a property’s value.² Treasury Regulation 1.263(a)-3 then supplies the test used to decide whether a given expense is actually an improvement. It’s known as the BAR test, and an expense that meets any one of the three parts has to be capitalized.³

Betterment

A betterment fixes a defect that existed before you bought the property, materially adds to its size or capacity, or increases its productivity or efficiency. Adding a second story, installing bolts that strengthen a building’s seismic resistance, or swapping in an HVAC system with substantially higher output all qualify. The question is whether the work made the property measurably better than its prior condition, not whether it simply made it work again.

Adaptation

Adaptation means converting a property to a use it was not designed for. Turning a residential garage into a commercial office, or a warehouse into a restaurant, forces capitalization because the work creates a new kind of utility. Cosmetic changes that don’t alter the property’s fundamental function don’t meet this test.

Restoration

Restoration covers replacing a major component or bringing a property back to working condition after it has deteriorated to the point of not functioning. Replacing an entire roof, rebuilding a plumbing network, or gutting and reconstructing a building that has fallen into disrepair all count.⁴ Patching a few shingles does not. The line falls between fixing a discrete piece and overhauling an entire system.

Capital Improvement or Repair?

A repair keeps the property in its current operating condition. An improvement makes it better, longer-lasting, or suitable for something new. IRS Publication 523 spells out the difference with examples familiar to any homeowner: painting (interior or exterior), fixing leaks, filling cracks, and replacing broken hardware are repairs. A new roof, a kitchen remodel, central air conditioning, a new driveway, or an added bathroom are improvements.⁵

One wrinkle catches people off guard. A repair performed as part of a larger improvement project is itself treated as part of the improvement. Replacing a few broken windowpanes on its own is a repair; replacing those same panes as part of a whole-house window replacement is an improvement.⁵ The surrounding project matters as much as the work itself.

For rental and business property, the tangible property regulations analyze each building system separately. Replacing the entire HVAC system is a restoration of that system even though the rest of the building remains standing. Cleaning up contaminated land you purchased is a betterment because it fixes a pre-acquisition defect. Building a stairway and loft to add selling space in a retail building is a betterment because it materially adds capacity.⁴

Tax Treatment for a Home You Live In

You don’t deduct or depreciate improvements to your personal residence. You add their cost to the home’s basis, and that adjusted basis is what you use to figure gain when you sell.

Basis starts with the purchase price plus certain closing costs such as title insurance, legal fees, and title search charges.⁶ Each capital improvement gets added on top. Say you bought a home for $300,000 and spent $50,000 over the years on a new roof, a kitchen remodel, and a finished basement. Your adjusted basis is $350,000. Sell for $450,000 and the gain is $100,000, not $150,000. Every documented improvement dollar reduces the taxable gain dollar for dollar.⁵

Not everything you spent at closing qualifies. Costs connected with getting a loan, casualty insurance premiums, and pre-closing rent or utility charges are excluded from basis.⁶ And improvement costs for items that are no longer part of the home when you sell, like carpeting you installed and later tore out, don’t count either.⁵

The Section 121 Exclusion

Many homeowners pay no capital gains tax on a sale at all. Section 121 lets you exclude up to $250,000 of gain ($500,000 if married filing jointly) on the sale of your principal residence, provided you owned and used the home as your main residence for at least two of the five years before the sale.⁷ That exclusion makes basis tracking feel less urgent, but it’s a mistake to skip it. If the home has appreciated well past the exclusion, if you’ve owned it for decades, or if you can’t meet the two-year use test, the adjusted basis is your primary defense against a sizable tax bill.

Insurance Reimbursements

If the property suffers casualty damage and you receive insurance proceeds, those proceeds reduce your basis. Subtract the insurance reimbursement and any deductible casualty loss from basis first; then add back what you spend restoring the property.⁸ The order matters. Skipping the reduction inflates basis and understates the eventual gain.

Tax Treatment for Rental and Business Property

For rental and business property, you don’t just hold improvement costs in basis until sale. You recover them through depreciation, claimed annually on Form 4562, with each project starting its own schedule in the month it is placed in service.

Recovery Periods

Residential rental property: 27.5 years for the building and structural components. Additions and improvements use the same 27.5-year period as the original structure, depreciated as separate items using the mid-month convention.⁹
Nonresidential (commercial) real property: 39 years for buildings placed in service after May 1993.¹⁰
Land improvements: 15 years for items like fences, sidewalks, paved parking areas, and swimming pools.¹⁰

Bonus Depreciation and Qualified Improvement Property

The One, Big, Beautiful Bill Act permanently restored 100% first-year bonus depreciation for qualified property acquired and placed in service after January 19, 2025, ending the phasedown schedule that had been reducing the percentage each year under the Tax Cuts and Jobs Act.¹¹ What that means in practice depends on the type of improvement:

Qualified improvement property (QIP): interior improvements to nonresidential buildings, including drywall, interior doors, ceilings, electrical, plumbing, and HVAC work, qualify for 100% bonus depreciation. Building enlargements, elevators, escalators, and structural framework changes don’t.
Land improvements: 15-year property such as fences and parking areas qualifies.
The buildings themselves (residential rental and commercial) have recovery periods over 20 years, so they stay on straight-line depreciation and don’t qualify for bonus.

Land improvements also don’t qualify for Section 179 immediate expensing, even though they do qualify for bonus depreciation.¹⁰ The rules here are counterintuitive, and owners often trip up by assuming one deduction applies because another one does.

Partial Disposition Election

When you replace a major building component like a roof or an HVAC system, you aren’t just adding an improvement. You’re also disposing of the old component. Treasury Regulation 1.168(i)-8(d)(2) lets you elect to recognize a loss on the remaining undepreciated value of what you replaced.¹² You make the election simply by reporting the loss on a timely filed return for the year of the replacement; no special form or election statement is required. Skip it and you’ll keep depreciating an asset that no longer exists while also depreciating its replacement.

Safe Harbors That Let You Skip Capitalization

Not every expense requires the full BAR analysis. Three safe harbors let you deduct certain costs immediately, even when they might otherwise read as improvements.

The de minimis safe harbor lets you deduct items costing $2,500 or less per invoice (for taxpayers without audited financial statements), provided you have a written accounting policy in place at the start of the tax year treating these costs as expenses for both book and tax purposes. The $2,500 threshold has been in effect since 2016.⁴ Without the written policy, the safe harbor is unavailable.

The safe harbor for small taxpayers applies if you own or lease a building with an unadjusted basis of $1 million or less and have average annual gross receipts under $10 million. You can deduct repair and improvement costs on that building outright, as long as the total for the year does not exceed the lesser of $10,000 or 2% of the building’s unadjusted basis.⁴ For a building with a $400,000 unadjusted basis, that cap is $8,000.

The routine maintenance safe harbor covers activities you reasonably expect to perform more than once during a building’s first ten years of service. For non-building property, the test is more than once during the asset’s class life.⁴ Repainting, replacing worn carpet in rental units, and servicing an HVAC system are typical examples.

Energy-Efficient Improvements

The Section 25C Energy Efficient Home Improvement Credit, which gave homeowners 30% back on qualifying upgrades like heat pumps, insulation, windows, and doors, expired for property placed in service after December 31, 2025.¹³ If you installed qualifying equipment before that date and haven’t yet claimed the credit, you can still claim it on the return for the year the property was placed in service. No equivalent residential energy improvement credit exists for 2026 installations at this time.

On the commercial side, the Section 179D deduction for energy-efficient commercial buildings is still available. It is based on the energy savings achieved by the building’s envelope, lighting, or HVAC systems relative to a reference standard, with substantially higher per-square-foot amounts for projects meeting prevailing wage and apprenticeship requirements.¹⁴

Records You Need to Keep

Good records are the only thing standing between your capital improvement deductions and an audit adjustment. For every project, keep:

Itemized invoices describing the work performed and the materials used.
Proof of payment: cancelled checks, bank statements, or credit card receipts showing the amount and date.
The project timeline, including when construction began and when the project was completed, since that determines when depreciation starts for rental property.
Building permits, which confirm the work was legally performed and serve as independent evidence that it occurred.

Organize files by building system (electrical, plumbing, HVAC, structural, and so on). That makes it much easier later to figure out which system a future repair relates to, which matters both for the BAR analysis and for a partial disposition election.

Records tied to property basis must be kept until the statute of limitations expires for the year you dispose of the property. In practice, that means holding improvement records for the entire time you own the property, plus at least three years after the return that reports the sale. If you received the property in a nontaxable exchange, you need records for both the old and new property until the limitations period closes on the year you dispose of the new one.¹⁵ Owners who hold properties for decades sometimes lose track of the early improvement records. Digital copies in the cloud are worth the effort.

Misclassifying an improvement as a deductible repair is one of the more common audit triggers for rental property owners. The IRS can reclassify the expense, disallow the current deduction, and assess an accuracy-related penalty of 20% on the resulting tax underpayment when the error results from negligence or disregard of the rules.¹ Organized records, a consistent written accounting policy, and a reasonable basis for each call are the best defenses when the IRS asks how you treated a given expense.

1
eCFR. 26 CFR 1.6662-2 – Accuracy-Related Penalty
2
Office of the Law Revision Counsel. 26 USC 263 – Capital Expenditures
3
eCFR. 26 CFR 1.263(a)-3 – Amounts Paid to Improve Tangible Property
4
Internal Revenue Service. Tangible Property Final Regulations
5
Internal Revenue Service. Publication 523, Selling Your Home
6
Internal Revenue Service. Publication 551, Basis of Assets
7
Office of the Law Revision Counsel. 26 USC 121 – Exclusion of Gain From Sale of Principal Residence
8
Internal Revenue Service. Publication 547, Casualties, Disasters, and Thefts
9
Internal Revenue Service. Publication 527, Residential Rental Property
10
Internal Revenue Service. Publication 946, How To Depreciate Property
11
Internal Revenue Service. Notice 2026-11 – Interim Guidance on Additional First Year Depreciation Deduction Under Section 168(k)
12
Internal Revenue Service. Examining a Taxpayer Electing a Partial Disposition of a Building
13
Office of the Law Revision Counsel. 26 USC 25C – Energy Efficient Home Improvement Credit
14
Internal Revenue Service. Energy Efficient Commercial Buildings Deduction
15
Internal Revenue Service. How Long Should I Keep Records