Cost Segregation Studies: Accelerating Depreciation on Commercial Real Estate

By Yarik Yarosh, CPA ·September 5, 2026 ·3 min read

Written by Yarik Yarosh, CPA (US & Canada) September 5, 2026 · FL CPA license AC61704 · CPA Ontario

A cost segregation study is an engineering-based analysis that identifies and reclassifies personal property assets and land improvements that are typically grouped with the building for depreciation purposes. Instead of depreciating the entire building over 39 years (commercial) or 27.5 years (residential rental), a cost segregation study separates components into shorter recovery periods: 5-year, 7-year, and 15-year property. Combined with 100% bonus depreciation (permanently restored under the OBBBA), a cost segregation study can produce massive first-year deductions.

✓Key takeaway

Cost segregation fundamentals:

What gets reclassified:
- 5-year property: Decorative finishes, removable carpet, specialty lighting, security systems, phone/data wiring, certain plumbing fixtures
- 7-year property: Office furniture, kitchen equipment, certain fixtures
- 15-year property: Landscaping, parking lots, sidewalks, fencing, exterior signage, site drainage, retaining walls (land improvements)
- Remains 39-year: Structural walls, foundation, roof structure, HVAC ductwork integrated into the building
Typical reclassification percentages:
- Office buildings: 15-25% of building cost moves to shorter lives
- Restaurants: 30-40% (heavy kitchen equipment, specialty finishes)
- Hotels: 25-35% (furniture, fixtures, specialty finishes)
- Retail: 20-30% (tenant improvements, display fixtures)
- Medical offices: 20-30% (specialized plumbing, electrical)
- Manufacturing: 25-40% (process-related components)
When to do a study:
- New construction or major renovation over $500,000
- Purchase of an existing building (the study can be done retroactively with a “look-back” study, claiming missed depreciation via Form 3115)
- Any time the building cost exceeds the study fee by a significant margin (studies cost $5,000-$15,000 for most small commercial properties)
Bonus depreciation interaction. With 100% bonus depreciation, all reclassified 5-year, 7-year, and 15-year property is deducted in full in Year 1. This is what creates the large first-year deduction.

How much does a cost segregation study save?

Hypothetical example

Round numbers. A business owner purchases a $1,000,000 commercial building (land value excluded: building value = $800,000). Without a cost segregation study, the building is depreciated straight-line over 39 years.

Without cost segregation:

Annual depreciation: $800,000 / 39 = $20,513/year
Year 1 deduction: $20,513
Tax savings at 32%: $6,564

With cost segregation study: The study identifies:

$120,000 in 5-year property (15% of building cost)
$40,000 in 7-year property (5%)
$80,000 in 15-year property (10%)
$560,000 remaining 39-year property (70%)

With 100% bonus depreciation:

5-year property: $120,000 (fully expensed in Year 1)
7-year property: $40,000 (fully expensed in Year 1)
15-year property: $80,000 (fully expensed in Year 1)
39-year property: $560,000 / 39 = $14,359 (Year 1 depreciation)
Total Year 1 deduction: $254,359
Tax savings at 32%: $81,395

Additional Year 1 tax savings from cost segregation: $74,831 ($81,395 - $6,564)

Cost of the study: $8,000-$12,000 Return on investment: 6x-9x in Year 1 alone

The catch is depreciation recapture. If the building is sold later, the accelerated depreciation is recaptured: 5-year and 7-year property at ordinary rates (Section 1245), 15-year property at ordinary rates, and 39-year property at 25% (unrecaptured Section 1250 gain). The time value of the upfront deduction usually outweighs the future recapture, but the analysis depends on the holding period and expected sale price.

Illustrative numbers only, not a real client and not advice for your facts.

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Cite this page

Yarik Yarosh, CPA. "Cost Segregation Studies: Accelerating Depreciation on Commercial Real Estate." Blue Cloud CPA, September 5, 2026. https://bluecloudcpa.com/guides/small-business-cost-segregation-study

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.