Cost segregation estimates for the same property can differ meaningfully between providers. That leaves many investors unsure what to expect from a cost segregation study.
Understanding how depreciation estimates work puts you in control. You can evaluate proposals with confidence and set realistic expectations for your tax savings. This article explains why estimates vary, what drives accuracy, and how to read the low-to-high ranges you receive.
Why Depreciation Estimates Vary
Most reputable cost segregation providers give a preliminary estimate before completing a full engineering study. These early figures help investors decide whether a study makes financial sense. But two providers looking at the same property often produce different numbers.
Several factors drive the variation:
- Property type and age affect which components qualify for acceleration
- Construction quality and materials influence asset classification
- Regional cost differences change replacement-cost calculations
- Estimator methodology ranges from conservative to aggressive
Preliminary estimates rely on limited information. Providers usually work from basic details like property type, purchase price, and square footage. A full engineering-based study with a site visit produces far more precise results. The IRS treats a detailed, engineering-based analysis as the most reliable approach in its Cost Segregation Audit Techniques Guide.
Consider a $2 million multifamily property. One provider might project $180,000 in accelerated depreciation. Another projects $260,000. Both can be reasonable, depending on their assumptions.
The conservative figure assumes older construction, standard finishes, and minimal land improvements. The aggressive figure assumes newer construction, premium upgrades, and extensive site work. Neither is necessarily wrong. They simply reflect different assumptions about what the study will uncover.
The Anatomy of a Study Range: Low, Mid, and High
Most reputable providers present a range rather than a single figure. That reflects the reality that outcomes depend on property-specific factors only a full study can confirm.
The low end represents worst-case assumptions: older properties, standard finishes, minimal personal property, and limited land improvements.
The high end reflects best-case conditions: newer construction, premium upgrades, extensive landscaping, and specialized systems.
The midpoint represents the most likely outcome based on comparable properties. In our experience, final results on well-prepared estimates tend to land close to the midpoint.
If I get the low end of the range, does that mean the study wasn't worth it?
Usually not. Even conservative results typically deliver a strong return. Consider a $1.5 million retail strip center with an estimated range of $90,000 to $150,000 in reclassified assets.
The math on the low end:
- Purchase price: $1,500,000
- Land value allocation (20%, property-specific): $300,000
- Depreciable basis: $1,200,000
- Accelerated depreciation (low estimate): $90,000
- First-year deduction value at a 37% marginal rate: $33,300
The top federal marginal rate for 2025 is 37%; your own savings scale with your bracket. A study commonly costs from about $1,000 for a simple residential desktop report up to $15,000 or more for a full commercial engineering study, depending on size, property type, and whether a site visit is included. Even the low-end result is often many times the study fee.
One caveat matters here: cost segregation accelerates deductions rather than creating new ones. It is primarily a timing and cash-flow benefit, and part of it is recaptured when you sell (more below). Whether you can use the deduction in year one also depends on your tax situation; see the note on passive losses below.
Land allocation is property-specific. The 20% figure above is illustrative; your allocation is typically based on the county assessor ratio or an appraisal, and it directly changes your depreciable basis.
What Drives Estimate Accuracy?
The quality of information you provide directly affects how close your estimate lands to the final result. Four factors matter most:
- Construction documentation such as blueprints, invoices, and appraisals
- Property condition and improvements made since acquisition
- Accuracy of the initial property details you share during the proposal
- Experience of the engineering team conducting the study
Investors who share detailed information upfront receive more accurate estimates. Vague or incomplete details force providers into broader assumptions.
Can I do anything to land closer to the high end?
Yes. Thorough documentation helps engineers identify every qualifying component.
Share renovation invoices. Recent improvements often qualify for bonus depreciation when properly documented.
Provide original blueprints. Construction drawings help engineers spot specialized systems that might otherwise be missed.
Document recent upgrades. New HVAC, parking-lot repairs, landscaping, and tenant improvements all affect results.
The One Big Beautiful Bill Act (OBBBA) restored a permanent 100% bonus depreciation deduction for qualifying property acquired and placed in service after January 19, 2025, according to IRS guidance. Two conditions are easy to miss. First, both the acquisition and the placed-in-service date must fall after that cutoff, property under a written binding contract before January 20, 2025 generally follows the prior phase-down schedule (40% for 2025). Second, bonus depreciation applies to the short-lived components a study reclassifies (5-, 7-, and 15-year property), not to the building structure itself. That makes accurate documentation more valuable, because every qualifying dollar identified can generate an immediate first-year deduction.
Real-World Accuracy: What the Data Shows
Estimates exist because real estate is complex. So how close are they in practice? Across completed studies, results generally cluster near the midpoint of a well-prepared estimate, with outliers usually tracing back to incomplete initial information or unexpected property conditions.
Typical reclassification ranges by property type (share of depreciable basis moved into shorter-lived classes):
Warehouses and plain industrial buildings tend to sit at the lower end, because much of their value is in the structure itself. Facilities with heavy specialized systems can run higher.
An illustrative example: a $3.2 million industrial warehouse receives an estimate of $320,000 to $480,000 in accelerated depreciation, with a $400,000 midpoint. The final study identifies $412,000 in reclassified assets — about 103% of the midpoint, and roughly 13% of the purchase price, consistent with the lower-to-middle end of the warehouse range once land is excluded.
For an investor in the top 37% bracket who can use the deduction, $412,000 could shelter about $152,440 of income in the first year. Whether that benefit is available immediately depends on your tax profile.
A note on when you can use these deductions. These first-year figures assume you can offset the losses against your income. Under the passive activity loss rules (IRS Publication 925), a typical investor without Real Estate Professional Status, or without qualifying short-term-rental material participation, may have the losses suspended until they have passive income or sell the property. For those who qualify, the deductions can offset ordinary income directly.
Red Flags: When an Estimate Doesn't Add Up
Not every estimate deserves your trust. Some providers use inflated projections as a sales tool rather than a realistic forecast. A projection of 45% acceleration on a retail property that typically yields 15-30%, for instance, warrants a closer look.
Warning signs include:
- Single-point estimates with no range
- Projections far above what the property type typically supports, with no explanation
- Unwillingness to explain methodology or assumptions
- No discussion of property-specific variables
- Guarantees of a specific outcome before conducting a study
Credible providers explain their assumptions and acknowledge uncertainty. They discuss what could push results toward the low or high end, and they don't guarantee outcomes before completing the engineering analysis. As a provider ourselves, we'd rather you understand the range than chase the highest number, a realistic estimate protects you at audit and at sale.
What should I do if one estimate is far higher than the others?
Ask for the methodology. Have the provider explain their assumptions and what would need to be true for the estimate to materialize. An unusually high projection with no supporting rationale may reflect aggressive assumptions that may not hold up under IRS scrutiny.
Remember that recapture applies when you sell. The 5- and 7-year personal property a study reclassifies is section 1245 property, recaptured at ordinary income rates up to 37%. The 15-year land improvements and the building itself are section 1250 property: depreciation claimed in excess of straight line, which bonus depreciation front-loads on 15-year assets, is recaptured as ordinary income, while the straight-line portion is unrecaptured section 1250 gain, capped at 25%.
Recapture can be deferred through a 1031 exchange, and under current law the basis step-up at death eliminates it, though that is an estate-planning outcome for your heirs, not a strategy for your own exit. Overstated depreciation today simply shifts a larger bill to the sale.
If you already own the property and previously used straight-line depreciation, you'll need Form 3115 to change your accounting method. A catch-up adjustment under Section 481(a) lets you claim the missed depreciation in the current year without amending prior returns, as described in the IRS Form 3115 instructions. A reputable provider will raise this upfront.
Setting Realistic Expectations for Your Study
Treat estimate ranges as realistic possibilities, not guarantees. The spread exists because properties vary. Even similar buildings contain different components, finishes, and improvements.
A range reflects complexity, not indecision. A provider who gives you a $200,000 to $300,000 range is being honest about what the engineering analysis might uncover. They are not hedging their competence.
Focus on after-tax return rather than the highest possible number. A $250,000 result generates roughly $92,500 in first-year deduction value at a 37% marginal rate, for an investor who can use it, and the study fee pays for itself in most cases, regardless of where you land in the range.
Key Takeaways
- Estimates vary because of property-specific factors, estimator methodology, and available documentation, not because the number is arbitrary.
- A low-to-high range reflects genuine complexity, and final results tend to land near the midpoint of a well-prepared estimate.
- Typical reclassification runs about 20-35% of depreciable basis, depending on property type, with warehouses at the lower end and multifamily and medical office higher.
- You can improve accuracy by sharing blueprints, invoices, and renovation records upfront.
- Bonus depreciation is now a permanent 100% for property acquired and placed in service after January 19, 2025, but only the short-lived components qualify, and passive activity rules may affect when you can use the deduction.
- Be cautious of any estimate that lacks a range, skips methodology, or guarantees an outcome.
Understanding how estimates work helps you evaluate proposals confidently and set expectations that lead to satisfaction, not surprises.
Want to know what's realistic for your specific property? Request an engineering-based estimate from R.E. Cost Seg and see the range, with the assumptions behind it, before you commit.
