Summary
The time a cost segregation study takes is mostly waiting: for a site visit to be scheduled, for the engineer's analysis, for the draft, for the review. SegFlow removes the waiting by producing the study from what the preparer uploads. The sequence is: create the study, upload documents and images, confirm the intake assumptions, run, and download the PDF (Portable Document Format) study, the Word version and the Excel ledger within an hour. This paper walks through each step, shows what the deliverables contain, gives an illustrative timeline for a short-term rental, and is specific about what the hour does and does not include.
Where the weeks go
A traditional engineered study needs a site inspection, so it begins with scheduling among the engineering firm, the owner and the property manager. The engineer then works up the take-off and cost allocation, a drafter formats the report, a senior reviewer checks it, and you receive it and review it again. Each handoff waits on a calendar, and in the fourth quarter, when most planning decisions are made, the queues are longest. None of this reflects the difficulty of the analysis for a rental house or a small building. It reflects the number of people and trips involved.
The SegFlow sequence
Create the study. The preparer enters the address, the use type (long-term rental, short-term rental or commercial), the purchase price, the closing date, the land value if known, the square footage and the year built. Each field maps to a rule. The closing date decides whether the property was acquired after January 19, 2025 and qualifies for 100% bonus depreciation under the 2025 budget reconciliation law (the One Big Beautiful Bill Act), and whether it was placed in service in a prior year, which means a Form 3115 change in accounting method rather than a current-year study. The use type decides whether the building is residential rental property at 27.5 years or nonresidential real property at 39.
Upload. The preparer uploads the closing statement or purchase contract, the county assessor record, and photos of every room, the four exterior sides, the mechanical spaces and the site. There is no client portal. A photo checklist can be forwarded to the owner by email; the owner replies with photos and the preparer uploads them.
Confirm intake. Before the study runs, SegFlow reads the uploads and shows one card: what it found (price, closing date, land value, square footage, year built, whether the property appears furnished), the assumptions it will make unless changed, and at most two or three questions that change the result, such as the source of the land value, the average customer stay, whether the property was furnished at purchase, and the look-back year. Anything that cannot be photographed can be described in text on this card.
Run. Payment is per study, $299 for residential (one to four units, including short-term rentals) and $699 for light commercial and multifamily, or a code. Two passes then run: an author pass that writes the ledger and a second, independent pass, the review pass, that checks it and writes the review notes. White paper 03 describes them.
Download. Inside an hour of upload, three files are ready.
What the deliverables contain
The PDF study opens with a cover and an executive summary that states the first-year deduction with and without the study. It then sets out the property and basis, a one-page method organized against the 13 principal elements of the Internal Revenue Service (IRS) Cost Segregation Audit Techniques Guide (ATG, the examiner's handbook for these studies), the schedule of components by class, the depreciation table, the review notes for the CPA (certified public accountant), and the assumptions and limitations. It states that it was prepared with software assistance for review by the taxpayer's preparer. The Word version is the same document, for firms that edit before issuing it under their own letterhead.
The Excel ledger is the workpaper. Each line carries the component name, quantity and unit, location, the evidence photo identifiers, the cost source, the raw and reconciled cost, the class, and the authority for the class: IRC (Internal Revenue Code) §1245 or §1250, Treas. Reg. §1.48-1(e)(2), the Rev. Proc. 87-56 asset class, or a case. Two further sheets list the exclusions with reasons and the assumptions. Edits are made in Excel or Word after download; the ledger is not edited inside the tool.
An illustrative timeline
Round numbers for illustration; this is not a client engagement. On a Monday at 9:05 a preparer creates a study for a furnished short-term rental bought in March 2026 for $650,000. By 9:20 she has uploaded the closing statement, the assessor printout, a booking export from the owner, and 38 photos the owner sent in reply to the checklist email.
The intake card shows: purchase price $650,000, closing March 12, 2026, assessor land value $110,000, three bedrooms and two baths over 1,900 square feet, photos covering every listed room and all four sides, no photo of the water heater or air handler. Assumptions: average customer stay under seven days based on the booking export, so the building is treated as nonresidential at 39 years and the furnishings as 5-year property; the mechanical equipment is assumed to be standard for the house and carried as a stated assumption. Two questions: use the assessor land value or the appraisal, and was the property furnished at purchase or afterward. She answers assessor and at purchase, pays $299, and runs the study at 9:30.
At 10:10 the three files are downloadable. She spends about an hour with the review notes and the ledger that afternoon. On Wednesday the owner sends the two mechanical photos, and she requests the included update. Version 2 arrives that afternoon with a page listing what changed and why: the air handler and water heater are confirmed as structural components at 39 years, the assumption is closed, and the totals by class before and after are shown unchanged. Not every update raises the deduction. Every update closes an assumption.
What the hour includes, and what it does not
The hour runs from completed upload to downloadable files. It does not include the owner's time collecting photos, the preparer's review, or the second run. One update is included after delivery, when the preparer adds documents, photos or comments on the review notes; both passes run again and version 2 arrives with its change page. There is no third run. Questions go to admin@segflowai.com and are answered within one business day.
Speed and quality are one design
Speed comes from removing handoffs while keeping every check. The review pass tests the ledger for duplicates, misclassification, cost outliers, benchmark deviation and defaulted inputs before the files are released, and the review notes direct the preparer to the items that need professional judgment. The preparer is the reviewer of record, and the study is written to make that review fast: evidence, class, authority and cost source on every line.
What this means for your firm
A study that returns within the hour changes how the service is sold. The conversation with a client who has just closed can end with a study in hand rather than a referral and a wait. Studies can be batched in the weeks before extensions and year-end without depending on another firm's calendar. The time your firm spends is review time on your own workpaper, and the intake card shows before you pay whether the uploads are enough to support a result you would sign.