How Cost Segregation Works

A plain-language walkthrough of how a cost segregation study puts real cash back in your pocket in year one — and what the process looks like when you work with Cascade.

Will Wightman

Owner Of Cascade Cost Seg

Quick take: Most property owners recover somewhere between 2% and 10% of their purchase price as a tax reduction in the very first year of ownership, with additional savings continuing in the years after. Here's how that actually works.

Depreciation, the short version

The IRS lets you deduct the cost of an income-producing property over time, as it wears down — that's depreciation. By default, residential rental property depreciates over 27.5 years and commercial property over 39 years, spread out evenly (straight-line) year after year. Land doesn't depreciate at all; only the building and what's in it.

The problem: that default schedule treats your entire building as one asset with one long lifespan. In reality, a property is made up of dozens of components that wear out — and get replaced — on very different timelines.

What a cost segregation study actually does

A cost segregation study is an engineering-based analysis that breaks your property down into its individual components and reclassifies them into the IRS categories they actually belong in.

Items like carpet, cabinetry, certain electrical and plumbing, and site improvements typically qualify for 5, 7, or 15-year depreciation schedules instead of being lumped in with the 27.5- or 39-year building shell. Our team works from your appraisal, construction documents, cost data, and (when needed) a site walkthrough to allocate your property's cost basis correctly and defensibly.

The result: instead of depreciation trickling in evenly over decades, a much larger share of your deductions become available in the early years you own the property — when that cash flow matters most.

Bonus depreciation in 2026

Bonus depreciation doesn't create more total depreciation — it changes when you get to claim it. Under current law (the One Big Beautiful Bill Act), qualifying property placed in service after January 19, 2025 is eligible for 100% bonus depreciation, meaning every dollar a cost seg study reclassifies into a 5, 7, or 15-year category can potentially be deducted in year one, all at once, rather than spread out over its normal schedule.

The building structure itself still depreciates over 27.5 or 39 years — bonus depreciation only applies to the shorter-life components a cost seg study identifies. This is exactly why the study matters: without it, there's nothing for bonus depreciation to accelerate.

A real example

Say you buy a $750,000 short-term rental.

  • Land (non-depreciable): 20% → $150,000

  • Depreciable basis: $600,000

  • Typically reclassified into 5/7/15-year categories: ~28% → roughly $168,000

  • At 100% bonus depreciation, that full $168,000 becomes available as a deduction in year one

  • At a 32% marginal tax rate, that's roughly $53,000+ back in year-one tax savings

Every property is different — this is just to show the mechanics. Your actual numbers depend on property type, purchase price, and your tax situation, which is exactly what a free estimate is for.

Why property owners work with Cascade

  • 1,000+ studies completed, with over $1B in depreciation identified and $10M+ in taxes deferred for our clients

  • Engineering-based, IRS-approved methodology — not a shortcut or a spreadsheet estimate

  • Studies start at $1,500, with portfolio discounts if you own multiple properties

  • Free audit defense — if the IRS ever questions your study, we defend it at no additional cost

  • One dedicated point of contact from your first call through your final report — not a call center