Getting Started

What Documents Do I Need for a Cost Segregation Study?

March 23, 2026 Jonathan Hersh 6 min read

The Short Answer

  • You need 6 pieces of information: purchase price, closing date, address, year built, property type, and renovation history
  • Most investors can provide everything in about 5 minutes
  • Your cost seg provider handles all engineering analysis, data collection, and report generation
  • Closing statements and tax assessments help but are not required

Most investors overthink this. A cost segregation study requires surprisingly little from you. Your provider handles the engineering analysis, construction cost research, and IRS classification work. You provide the basic property details—the same information you already know from buying the property.

There's a persistent misconception that ordering a cost seg study means digging through filing cabinets for blueprints, scheduling a property inspection, or gathering a stack of construction documents. That's not how modern studies work. Here's what you actually need.

What You Need to Provide

Six items. All of them are things you already know or can pull from your closing documents in a few minutes.

That's it. Five minutes of information that most property owners can provide from memory. No blueprints, no site visit, no construction documents.

Property documents for a cost segregation study
The information needed for a cost segregation study is the same basic property data you collected when you bought the property.

What Your Provider Handles

The heavy lifting in a cost segregation study is the engineering analysis, not the data collection from you. Here's what a qualified provider does with the six inputs you provide:

County assessor data

Square footage, lot size, construction type, assessed values, and building characteristics pulled from public records.

Satellite and aerial imagery

Property footprint, site improvements, landscaping, driveways, patios, pools, and other 15-year land improvements identified remotely.

Construction cost databases

RSMeans cost data adjusted for geography, property age, and construction type. This establishes replacement cost at the component level.

Engineering analysis

Every building component classified into its correct MACRS recovery period (5, 7, 15, 27.5, or 39 years) per IRS guidelines.

Land valuation

Multi-source pipeline using assessor data, statistical metro models, and property-specific adjustments to separate land from depreciable basis.

Report generation

A 30+ page PDF with depreciation schedules, component-level breakdowns, and methodology documentation ready for your CPA to file.

The provider's job is to take your basic property information and produce an IRS-defensible report that your CPA can use to reclassify assets on your tax return. You don't need to understand RSMeans cost data or Rev. Proc. 87-56 asset classifications. That's what you're paying for.

Documents That Help but Aren't Required

Certain documents can improve the accuracy of your study. If you have them handy, include them. If you don't, your provider can still produce a complete, defensible report without them.

Closing statement (HUD-1 or Closing Disclosure)

Confirms the exact purchase price, closing date, and any seller credits or adjustments. Most useful when the transaction had unusual terms.

Tax assessment notice

Shows the county's land vs. improvement split, which helps calibrate the land valuation. Especially useful when the assessed land ratio differs significantly from statistical models.

Renovation invoices

If you've done significant work (kitchen remodel, addition, major systems replacement), invoices help quantify the improvement and classify components accurately.

Floor plans or architectural drawings

Helps identify room counts, specialty spaces (home theater, wine cellar, commercial kitchen), and building layout. Satellite imagery covers most of this, but floor plans add interior detail.

None of these are blockers. A study can proceed without any of them. They're refinements, not requirements. If you're debating whether to spend an hour hunting for your 2019 closing disclosure, the answer is: don't. Order the study now and provide it later if you find it.

Cost segregation study documentation process
Supporting documents like closing statements and tax assessments can refine accuracy, but your provider can produce a complete report without them.

For Look-Back Studies

If you've owned the property for one or more years and never had a cost segregation study done, you can still capture the missed depreciation through a look-back study. Your CPA files Form 3115 to claim a catch-up deduction in the current tax year—no amended returns needed.

For a look-back study, you'll need the same six items above, plus:

  • The year you placed the property in service (your first tax year claiming depreciation)
  • Your current depreciation schedule from your CPA or tax preparer

The depreciation schedule shows what you've already claimed, so the study can calculate the exact catch-up amount. If you don't have it readily available, your CPA can pull it from your prior returns.

What CostSegSmart Specifically Needs

Our process is designed around the reality that investors don't want to hunt for documents. Here's how it works:

From Order to Report

1 Enter your property details online. Address, purchase price, closing date, year built, property type, and any renovation notes. Takes about 5 minutes.
2 We pull everything else automatically. County assessor data, satellite imagery, construction cost references, geographic cost indices—all sourced from public records and industry databases.
3 Engineering analysis runs. Every component classified into the correct MACRS recovery period using RSMeans cost data and IRS-recognized methodology.
4 Report delivered to your inbox. A 30+ page CPA-ready PDF with depreciation schedules, component breakdowns, and methodology documentation. Delivered in under 1 hour.

No phone calls. No site visits. No back-and-forth requesting documents you can't find. The study is priced transparently based on property type and purchase price—starting at $795 for residential properties.

If you have a closing statement or tax assessment and want to upload it, we accept those too. They can refine the land valuation. But they're not gatekeepers to getting started. To see what your property's depreciation breakdown might look like before ordering, run the free calculator—it takes 60 seconds.

CostSegSmart report delivery
Enter your property details in about 5 minutes. We handle the rest and deliver a CPA-ready report in under an hour.

Frequently Asked Questions

What documents do I need for a cost segregation study?

Six basic inputs: purchase price, closing date, property address, year built, property type, and any renovation history. These are the same details you collected when you purchased the property. Supporting documents like a closing statement (HUD-1 or Closing Disclosure), tax assessment, or renovation invoices can improve accuracy but aren't required to get started.

Do I need a property appraisal for a cost segregation study?

No. A property appraisal is not required. Cost segregation providers use the purchase price as the primary valuation input and supplement it with county assessor data, construction cost databases, and satellite imagery. An appraisal can be useful in rare cases where the purchase price is significantly different from fair market value (a below-market family transaction, for example), but it's not a standard requirement.

How long does it take to gather the required information?

About five minutes. Most property owners know their purchase price, closing date, address, year built, and property type from memory. Renovation history is the only item that might require a moment of thought—and "no major renovations" is a perfectly valid answer. There are no complex forms, no blueprints to locate, and no inspections to schedule.

Ready in 5 Minutes. Report in Under 1 Hour.

Enter your property details and we handle the rest. Engineering-based analysis, CPA-ready report, IRS-defensible methodology.

See Your Depreciation Breakdown →
Disclosure This article is for informational and educational purposes only and does not constitute tax, legal, or financial advice. Cost Seg Smart is not a CPA firm, tax advisory firm, or law firm. Our engineering-based cost segregation reports are designed to be CPA-ready — meaning they should be reviewed by your qualified tax professional before filing. Every property and tax situation is different. Please consult your CPA or tax advisor before making any tax decisions based on the information in this article.