# Cost segregation after a renovation: improvements and partial dispositions

A renovation adds new assets and retires old ones. How improvements are capitalized, how a study classifies them, and how the partial disposition election works.

## Short answer

A renovation does two things to a depreciation schedule at once. It adds new assets, because amounts paid to better, restore or adapt a building are capitalized as improvements and depreciated as separate property with their own dates and classes. And it removes old ones, because the roof, kitchen or parking lot you tore out is gone, and the partial disposition election lets you retire its remaining basis instead of depreciating a component that no longer exists. A cost segregation study makes both halves possible: it classifies the new work item by item, and its asset list from the original acquisition is what tells you what the old component cost. Between those two sit the repair rules and their safe harbors, which decide whether some of the spending is deducted outright rather than capitalized at all. This article walks the sequence. It is general education, not tax advice.

## First question: repair or improvement?

Before anything is classified, your adviser decides what was capitalized. The tangible property regulations capitalize amounts paid for an improvement to a unit of property, which for a building means the building and its structural components, with its building systems, such as HVAC, plumbing, electrical, elevators, fire protection and security, analyzed separately. An amount is an improvement if it is a **betterment**, a **restoration** or an **adaptation to a new or different use**. Other amounts are repairs and are deducted.

Two safe harbors matter for rental owners. Small taxpayers with average annual gross receipts of $10 million or less may deduct amounts paid for repairs, maintenance and improvements to an eligible building with an unadjusted basis of $1 million or less if the year's total does not exceed the lesser of 2 percent of that basis or $10,000. And routine maintenance on a building, meaning work reasonably expected more than once in a 10-year period, is not an improvement. Small purchases may also fall under the de minimis safe harbor election covered in a separate article.

What survives those tests is capitalized, and that is what the study classifies.

## Second: classify the improvements

| What was done | Typical classification | Notes |
|---|---|---|
| New roof, structural work, exterior, windows | 27.5- or 39-year, part of the building | Restoration of the building |
| Replaced HVAC, plumbing or electrical serving the building | Building | Building systems are still part of the building for depreciation |
| Parking lot resurfacing, new fencing, site lighting, drainage | 15-year land improvements | Often bonus-eligible on their own dates |
| New appliances, flooring, window coverings, furniture | 5-year property | Bonus-eligible on their own dates |
| Dedicated electrical or plumbing serving equipment | 5- or 7-year on the facts | Function analysis, as in any study |

Each improvement is a separate depreciable asset with its own placed-in-service date, which is when it was complete and ready for use, and its own acquisition date for bonus depreciation. Renovation assets acquired after January 19, 2025 can qualify for the permanent 100 percent rule even when the underlying building did not. The study's asset list for the renovation reconciles to the renovation's capitalized cost, not to the original purchase.

## Third: retire what was removed

Without a study, a building is one asset on the schedule, and replacing its roof produces a strange result: the new roof is capitalized and depreciated, while the cost of the old roof, buried in the building line, keeps depreciating for decades. The partial disposition election fixes that. It lets you treat the disposition of a portion of an asset, the old roof, as a disposition, and recover its remaining basis as a loss in the year it was removed. The election is made by reporting the gain, loss or deduction on the timely filed original return for that year, and it generally cannot be revoked through a method change.

The practical problem is knowing what the old roof cost. If the acquisition study identified the roof, or the building's components, on its asset list, the answer is there. If it did not, the regulations allow any reasonable method to determine the disposed portion's basis, such as discounting the replacement cost back to the acquisition year or allocating pro rata by replacement costs. A practitioner can support that computation; it is one of the quieter reasons a study's asset list keeps paying for itself.

Note the sequence: the election is made for the year of disposition. An owner who replaces a roof and files without it has generally lost the election for that roof.

## Putting the three together on a value-add project

1. **Acquisition study** of the building as bought: land, land improvements, personal property, building, with an asset list.
2. **Renovation begins.** Track costs by trade and by unit; keep contracts, pay applications and invoices; note dates of completion by phase.
3. **Repair analysis** with the adviser: what is deducted under the safe harbors or as repairs, what is capitalized.
4. **Renovation study** of the capitalized work: classification, dates, reconciliation to the capitalized renovation cost.
5. **Partial dispositions** for components replaced, using the acquisition study's asset list or a reasonable method, elected on the return for the year of removal.
6. **Schedule update** carrying old assets, retired assets and new assets with their own dates. The IRS guide expects the study's asset list to tie to the fixed-asset ledger, and a renovation is where that tie earns its keep.

## Common errors

- Folding renovation costs into the original building line, losing the separate dates and the bonus analysis.
- Capitalizing everything, including repairs the safe harbors would have allowed as deductions, or deducting improvements.
- Never retiring the replaced component, so the schedule depreciates two roofs.
- Missing the partial disposition election by filing the year-of-removal return without it.
- Treating the renovation's placed-in-service date as the day the contractor was paid rather than the day the work was complete and usable.
- Forgetting that section 1245 recapture applies later to the renovation's personal property, as to any other.

## What people ask on Reddit and other forums

Renovation questions run through the "cost segregation reddit" threads on r/realestateinvesting and r/tax, usually after the work is done. The searches that lead people to these threads are usually phrased "partial asset disposition", "renovation depreciation rental property" and "capitalize or expense improvements".

**"I replaced the roof. Can I write off the old one?"** Through the partial disposition election, on the return for the year the old roof was removed, using its basis from the acquisition study or a reasonable method. Miss the year and the election is generally gone for that roof.

**"Is a new kitchen a repair or an improvement?"** A betterment, restoration or adaptation is an improvement and is capitalized; the small-taxpayer and routine-maintenance safe harbors can cover smaller work. Your adviser applies the tests to the facts.

**"Does the renovation get 100 percent bonus if I bought the building in 2023?"** The renovation assets have their own acquisition dates. Work acquired after January 19, 2025 can qualify on its own even though the 2023 building did not.

**"Do I need a second study for the renovation?"** Usually the renovation is studied as its own project with its own records, reconciled to its own capitalized cost, alongside the acquisition study.

## Questions people also ask

### What is a partial asset disposition?

An election under the depreciation regulations to treat the removal of a portion of an asset, such as a replaced roof, as a disposition, recovering its remaining basis in the year of removal instead of continuing to depreciate it.

### How do I know what the old component cost?

From the acquisition study's asset list if one exists; otherwise by a reasonable method the regulations permit, such as discounting the replacement cost to the acquisition year or a pro rata allocation.

### Are renovation costs eligible for cost segregation?

Yes. Capitalized improvements are classified item by item like any other asset, with their own dates, and their 5-, 7- and 15-year components can qualify for bonus depreciation on their own acquisition dates.

### What is the small taxpayer safe harbor?

For taxpayers with average annual gross receipts of $10 million or less, amounts paid for repairs, maintenance and improvements to a building with an unadjusted basis of $1 million or less may be deducted if the year's total does not exceed the lesser of 2 percent of that basis or $10,000.

### When is a renovation placed in service?

When the improvement is complete and ready and available for its use, phase by phase if the work is phased.

## Sources

- https://www.law.cornell.edu/cfr/text/26/1.263%28a%29-3 — 26 C.F.R. §1.263(a)-3: improvements (d); unit of property and building systems (e)(2); safe harbor for small taxpayers (h); routine maintenance safe harbor (i).
- https://www.law.cornell.edu/cfr/text/26/1.168%28i%29-8 — 26 C.F.R. §1.168(i)-8: partial disposition election (d)(2); asset for buildings (c)(4); basis of the disposed portion (f)(3).
- https://www.irs.gov/publications/p527 — IRS Publication 527 (2025), Residential Rental Property: Chapters 2 and 4.
- https://www.irs.gov/pub/irs-pdf/p5653.pdf — IRS Publication 5653, Cost Segregation Audit Techniques Guide (Rev. 2-2025): Chapter 4.
- https://www.irs.gov/newsroom/treasury-irs-issue-guidance-on-the-additional-first-year-depreciation-deduction-amended-as-part-of-the-one-big-beautiful-bill — IR-2026-06 (January 14, 2026), bonus depreciation guidance.
- https://www.irs.gov/publications/p544 — IRS Publication 544 (2025), Sales and Other Dispositions of Assets: Chapter 3.

## Related reading

- [Cost segregation for new construction versus an acquisition](/articles/new-construction-vs-acquisition)
- [Acquisition date vs placed-in-service date](/articles/acquisition-date-vs-placed-in-service-date)
- [The de minimis safe harbor and small purchases](/articles/de-minimis-safe-harbor-rental)
- [How to read a depreciation schedule](/articles/how-to-read-a-depreciation-schedule)
- [Depreciation recapture after cost segregation](/articles/depreciation-recapture-after-cost-segregation)
- [What Reddit asks about cost segregation, answered with sources](/articles/cost-segregation-questions-from-reddit)
- [Find a practitioner in the NBCSS directory](/directory)

---
Canonical: https://nbcss.org/articles/renovations-improvements-and-partial-dispositions
Published: 2026-09-25 · Last content change: 2026-09-25
Not professional advice: general educational information from the National Board of Cost Segregation Specialist (NBCSS); not accounting, tax, legal, financial, investment or engineering advice. Verify with a licensed CPA, enrolled agent, attorney or other qualified adviser before acting.