# Cost segregation questions to ask before buying a rental

The depreciation questions that are easiest to answer before closing: land share, contents, dates, contract timing, your passive position, state and exit.

## Short answer

Most of the questions that decide whether a cost segregation study will help are easier to answer before you buy than after. The land share of the price, what the property physically contains, whether it is residential or nonresidential, when the contract is signed and when the property will be ready to rent, whether you can use a loss this year, what your state does with bonus depreciation, and how you expect to exit: all of these can be settled during due diligence, when the documents are on the table and the dates can still be chosen. Buyers who ask them first commission studies that help and skip studies that would not; buyers who ask them in April get whatever the closing produced. This article is the pre-purchase list, with the rule behind each question. It is general education, not tax or investment advice.

## The list

| Question | Why it matters | Where the answer is |
|---|---|---|
| 1. How much of the price is land? | Land is never depreciated; the depreciable pool is what is left | Appraisal, assessor record, market evidence |
| 2. What does the property contain besides the structure? | Land improvements and personal property are what a study reclassifies | Walk-through, inventory, site plan |
| 3. Residential or nonresidential? | 27.5- versus 39-year building; transient use changes the answer | Rent roll, intended use, average stays |
| 4. When will the contract be signed and when will it close? | The acquisition date decides the bonus depreciation regime | Purchase agreement |
| 5. When will it be ready to rent? | Placed in service sets the start of depreciation and the convention | Condition, renovation plan, listing date |
| 6. Can I use a loss this year? | Passive activity rules decide whether a first-year deduction is a saving or a carryforward | Your adviser, your return |
| 7. What does my state do? | Decoupled states add bonus depreciation back | Your adviser, the state's tax authority |
| 8. How and when will I exit? | Recapture at sale; exchange planning | Your plan |
| 9. Will the seller give me the records? | Drawings, invoices, prior studies and schedules make a study cheaper and better | Due diligence request |

## Questions 1 and 2: what you are actually buying

Basis is allocated between land and building by fair market value at purchase, and the assessor's ratio may be used when values are uncertain. Get the appraisal's land value during due diligence and compare it with the assessor's record; if they disagree widely, ask why now. Then walk the property with the study in mind: parking, fencing, site lighting, drainage, landscaping, appliances, flooring, window coverings, furnishings, laundry and fitness equipment. A property with a high land share and few improvements has little for a study to find, whatever its price.

## Question 3: residential or nonresidential

A building is residential rental property if 80 percent or more of its gross rental income comes from dwelling units; transient units are not dwelling units. Mixed-use buildings and short-term rental plans can make a building nonresidential, which puts the structure on 39 years and, for short stays, changes the passive activity treatment. Decide the intended use before closing, because the answer shapes both the study and the return.

## Questions 4 and 5: the dates you can still choose

For bonus depreciation, property acquired under a written binding contract is treated as acquired no later than the contract date, and the permanent 100 percent rate applies to qualified property acquired after January 19, 2025. Most purchases today are past that line, but renovations, phased projects and assumed contracts can straddle it. Placed in service is when the property is ready and available for rent; a renovation between closing and listing moves it, and creates separate assets. Buyers who plan a renovation should plan its completion date and its records with the study in view.

## Question 6: your passive position

This is the question buyers most often skip and most often regret. Rental losses are generally passive. Unless you actively participate and fall within the special allowance, or you are a real estate professional who materially participates, or the property is a short-term rental business in which you materially participate, a first-year loss from a study is a suspended loss. Ask your adviser before closing what a loss would do on your return. The answer decides whether the study is a current benefit, a deferred one, or a fee.

## Question 7: state

Your state may add federal bonus depreciation back and allow its own depreciation over years, giving you a second schedule and a different state result. Ask before you rely on a combined-rate projection.

## Question 8: exit

Depreciation on the reclassified property is recaptured as ordinary income at sale; the building's depreciation is unrecaptured section 1250 gain at up to 25 percent. A short hold gives recapture time to undo the deferral; an exchange defers gain on the real property under its own rules. Decide the plan, then decide the study.

## Question 9: records

Ask the seller during due diligence for drawings, specifications, construction and renovation records, invoices for equipment and site work, any prior cost segregation study and the depreciation schedule. Sellers are cooperative before closing and unreachable after. The IRS guide's elements of a quality study begin with documentation and a site inspection; the records you collect now are the evidence the study will rest on.

## A due diligence sequence

1. Get the appraisal and the assessor record; settle the land question.
2. Inventory the improvements and contents with photographs.
3. Confirm the intended use and the residential question with your adviser.
4. Model your passive position and your state with your adviser.
5. Set the contract and closing dates with the bonus regime in view, and plan any renovation's completion.
6. Request the seller's records in the due diligence list.
7. Get a scoped estimate from a practitioner on that evidence, then decide.

## What people ask on Reddit and other forums

Buyers under contract ask the "cost segregation reddit" threads on r/realestateinvesting what to do before closing. The searches that lead people to these threads are usually phrased "questions before buying a rental property", "due diligence depreciation rental" and "cost segregation before closing".

**"Should I get the study before or after closing?"** After, on the final basis and documents, but decide whether to get one before, on the evidence above, and collect the seller's records while you can.

**"Does the closing date matter for bonus?"** The acquisition date does, and a written binding contract sets it no later than the contract date. Ask your adviser about your contract.

**"I'm buying a duplex I'll live in. Does any of this apply?"** Yes, to the rental part; a separate article covers house hacks.

**"The seller has a cost seg from 2019. Can I use it?"** As evidence of what the property contains, yes. Your basis, dates and study are your own.

## Questions people also ask

### What should I ask about depreciation before buying a rental?

The land share, what the property contains, residential or nonresidential use, contract and closing dates, when it will be ready to rent, your passive activity position, your state's rules, your exit plan and the seller's records.

### Can I plan the acquisition date for bonus depreciation?

The contract date and the closing date determine it under the binding-contract rule; plan them with your adviser.

### Does a high land value make a study pointless?

It reduces the depreciable pool. Whether a study is still worth it depends on the improvements and contents that remain.

### What records should I get from the seller?

Drawings, specifications, construction and renovation records, invoices for equipment and site work, any prior study and the depreciation schedule.

### Who should I talk to first?

Your tax adviser, with the appraisal and your return in hand; then a practitioner for a scoped estimate.

## Sources

- https://www.irs.gov/publications/p551 — IRS Publication 551 (Rev. December 2024), Basis of Assets.
- https://www.law.cornell.edu/uscode/text/26/168 — 26 U.S.C. §168(e)(2)(A), §168(c) and §168(k)(2)(E).
- 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/p946 — IRS Publication 946 (2025), How To Depreciate Property: Chapter 1.
- https://www.irs.gov/publications/p925 — IRS Publication 925 (2025), Passive Activity and At-Risk Rules.
- https://www.irs.gov/publications/p544 — IRS Publication 544 (2025), Sales and Other Dispositions of Assets: Chapters 3 and 4.
- https://www.irs.gov/pub/irs-pdf/p5653.pdf — IRS Publication 5653, Cost Segregation Audit Techniques Guide (Rev. 2-2025): Chapter 4.

## Related reading

- [Is cost segregation worth it? A decision checklist](/articles/is-cost-segregation-worth-it)
- [Acquisition date vs placed-in-service date](/articles/acquisition-date-vs-placed-in-service-date)
- [Land and building allocation](/articles/land-and-building-allocation)
- [Why a deduction is not a refund](/articles/why-a-deduction-is-not-a-refund)
- [Cost segregation and state taxes: conformity and decoupling](/articles/state-conformity-bonus-depreciation)
- [What Reddit asks about cost segregation, answered with sources](/articles/cost-segregation-questions-from-reddit)
- [Find a practitioner in the NBCSS directory](/directory)

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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.