Cost segregation, explained by an owl
Your building is hiding first-year deductions. Ollie finds them.
Most buildings are depreciated over 27.5 or 39 years — even the parts the tax code says can be written off in 5, 7, or 15. Ollie walks you through it in plain English, shows you the math free, and builds your study for $395.
The 60-second estimate
Free · no accountThe honest fine print: this estimate — and everything else on this site — is for educational purposes and isn't tax advice. Professional engineer/CPA review is not offered at this time. Talk to your tax advisor before acting on any of it.
What is cost segregation?
One building. Dozens of assets. Very different clocks.
The tax code doesn't see “a building.” It sees structure (27.5 or 39 years), land improvements like parking and landscaping (15 years), and personal property like carpet, cabinetry, and specialty electrical (5 or 7 years). Most owners depreciate everything on the slowest clock — because separating it takes an engineering study.
That study is cost segregation. It has been examined practice for decades, and the IRS publishes exactly what a quality study looks like. Ollie builds to that standard — and teaches you what he's doing at every step.
A $1M building, roughly speaking
Typical benchmark mix — the gold and teal bars are what a study moves onto faster schedules. Your mix depends on your property, which is the whole point of studying it.
How it works
Four steps. One very studious owl.
Tell Ollie about your building
Property type, what you paid, roughly how much is land. Sixty seconds, no jargon — Ollie translates everything into plain English as you go.
Ollie builds your study
Photos, closing documents, and invoices become an engineered component breakdown. The engine models all six IRS-recognized methodologies and recommends the one your evidence actually supports.
See your Completeness Score
Every study is graded 0–100% with an itemized gap report. No mystery, no black box — you see exactly what's well-supported and what's thin before anything is final.
Use your Completeness Score
Your study is an educational workpaper with an itemized gap report. A future licensed engineer/CPA professional review may be offered once a partner firm is onboarded — it is not available at checkout today.
Built on the IRS's own playbook
All six IRS-recognized methodologies. Scored against all 13 quality elements.
The IRS Cost Segregation Audit Techniques Guide describes six ways to build a study and thirteen elements a quality one contains. Ollie models every methodology your evidence qualifies for, recommends one with reasons, and grades the result — citations included.
Detailed engineering from actual costs
The gold standard when you built recently and kept records: invoices and pay applications priced line by line, reconciled to the penny.
Detailed engineering from inspection
No construction records? A component takeoff from a site inspection — Ollie's photo and video walkthrough AI does the heavy lifting.
Survey / letter approach
Vendors and contractors confirm what they installed and what it cost. Best when the people who built it are still a phone call away.
Residual estimation
Short-life property is measured; the remainder stays with the building. A pragmatic fit for smaller projects.
Sampling / modeling
Own several similar properties? A statistical model built on a template property covers the whole portfolio.
Rule-of-thumb
Percentages with no documentation. Ollie can show you what it looks like — and will tell you plainly why the IRS frowns on it. We never finalize one.
Pricing
Engineering-firm methodology. Owl-sized price.
Traditional cost segregation studies run $5,000–$15,000. Ollie does the takeoff with AI and shows his work — so you keep the methodology and skip the airfare.
- Full AI-engineered study, all qualifying methodologies
- Photo & video walkthrough takeoff
- Completeness & Accuracy Score with itemized gap report
- Depreciation schedules, fixed-asset export, printable report
- Look-back §481(a) catch-up math included
Provided as an educational workpaper — you and your tax preparer stay in the driver's seat.
- Optional licensed engineer/CPA review — not sold until a partner is live
- Today: educational workpaper + Completeness Score only
- Unlocked when your study scores above 90% complete
- Ollie shows you exactly what to add to qualify
Professional review is disabled until a CPA/engineering partnership is in place.
Questions owners actually ask
Ollie answers, honestly.
What actually is cost segregation?
Buildings normally depreciate over 27.5 or 39 years. But a building isn't one thing — carpet, cabinetry, dedicated electrical, parking lots, and landscaping are legally 5-, 7-, or 15-year property. A cost segregation study identifies and documents those components so you can deduct them on the schedule the tax code already allows. With bonus depreciation, much of it can land in year one.
Is this legit with the IRS?
Cost segregation is a well-established practice the IRS examines under its own Audit Techniques Guide (Pub 5653). Ollie's studies are built directly against that guide — the 13 principal elements the IRS looks for are scored on every study, with citations down to the Revenue Procedure and Code section.
Who is this for?
Owners of rental homes, short-term rentals, multifamily, offices, retail, industrial, hospitality, and medical buildings — typically anything with a depreciable basis of about $200k and up. The free estimate will tell you honestly if a study isn't worth it for your numbers.
Why is it $395 when firms charge $5,000+?
Traditional studies are priced around site visits, travel, and manual takeoffs. Ollie's AI does the takeoff from your photos, documents, and answers, against the same IRS methodology — and shows its work with a Completeness Score. You pay for the engineering logic, not the airfare.
Is professional engineer/CPA review available?
Not right now. Every study today is a self-directed educational workpaper with a Completeness Score. When Cost Seg Owl partners with a licensed engineer/CPA firm, optional professional review will return — gated on study quality — and we'll say so clearly on the site.
Do I need this before I file?
Studies are most powerful in the year the property is placed in service, but a look-back study with a Form 3115 catch-up adjustment can recover missed depreciation from prior years without amending returns. Ollie computes the §481(a) adjustment for you — then you and your tax preparer decide.