1. What the Study Actually Does
Standard depreciation treats the building as one 27.5-year asset. A cost segregation study takes the building apart on paper. Engineers and tax specialists perform it — not software guesses. - **5-year property:** appliances, carpet, cabinetry, window treatments - - **15-year property:** landscaping, paving, fences, some site improvements - **27.5-year:** the structural remains The reclassified pieces qualify for **100% bonus depreciation** — deducted entirely in year one. The whole effect: move deduction from the 2040s into this April.
2. Why STRs Changed the Math
In the long-term rental world, cost segregation often serves landlords whose passive losses they can't use. The short-term rental flips that. Short average stays plus material participation means losses can offset W-2 income *now*. The front-loaded depreciation has somewhere to go the year it is created. That is why a $400,000 STR with an active owner can justify a study the same-priced long-term rental cannot. Same building, same study cost — different usefulness.
3. The Honest Cost Side
A defensible study typically costs a few thousand dollars, rising with property complexity. The IRS expects engineering-based documentation. A spreadsheet you made yourself is not a study and will not survive review. The fee is deductible — which softens, but does not erase, the price.
4. When It Makes Sense
The profile where the math works: - Property basis of roughly $400,000 or more. Below that, the short-life pieces are usually too thin to matter - High marginal rate. A 32% bracket host gets more from each moved dollar than a 12% bracket host - **Material participation established, or clearly establishable** — the loss must be usable for the study to matter - You'll hold the property long enough to enjoy the deferral And when it doesn't: - Modest basis, modest income, losses already absorbed by the $25,000 offset - A likely sale within a few years. Recapture claws back the acceleration, and short holds can make the study a net loss - Participation unclear — front-loaded losses that suspend help nobody
5. Illustration, Not a Promise
A $500,000 property — building basis $410,000 after land — with a study reclassifying $95,000 into 5- and 15-year property. Year one: the standard $14,900 building slice, plus the entire $95,000 expensed under bonus. The host has $130,000 of W-2 income and documented participation. The deduction lands in the year it is worth the most. The trade: that $95,000 recaptures at sale, and the study cost came off the top. Whether that trade wins depends on your bracket, your holding period, and your participation file — which is why the study decision comes *after* the return fundamentals, never before.
6. Two Questions Hosts Ask First
**"Can I do this on a property I've held for years?"** Yes — a look-back study can catch up the missed depreciation, sometimes via an amended return or a Form 3115 change in accounting method. The economics improve when several years of reclassification land together. **"Does the study trigger audits?"** A properly documented engineering study is not itself a flag — aggressive positions *without* documentation are. The study exists precisely to carry the documentation burden.
7. The Sequence That Prevents Wasted Studies
1. Establish the schedule and the participation hours first 2. Model the standard loss first. Sometimes it is already fully usable, and a study buys nothing 3. Only then commission the study, sized to the property We run that sequence with Orlando hosts before anyone spends study money. Start secure intake or see how we work with hosts.
8. The STR Guides
This article is part of our short-term rental series: Orlando Airbnb taxes (start here), Schedule E or Schedule C, the seven-day rule, material participation, the host's 1099-K reconciliation, depreciation, and cost segregation.