Market guide · Methodology
How a commercial cost-segregation study is produced
Every credible study is engineering-based in the sense the IRS uses — components are identified, quantified and classified with support. What differs across providers is how the property is observed and how the components are priced.
The three approaches you'll encounter
1. Engineering site-visit
A trained inspector visits the property to measure, photograph and document assets, and the study is built from that plus construction and cost records. It is the traditional approach and is hard to fault on documentation; it costs more (travel and time) and takes longer. Some firms — see the provider comparisons — market a mandatory site visit on every study as a virtue.
2. Virtual / modeled
The property is observed remotely — plans, photos, video walkthroughs, equipment schedules and cost data — and components are quantified from that evidence. For large, repetitive, well-documented buildings (warehouses, self-storage, standard offices) a well-run virtual study can reach the same component detail at lower cost and faster turnaround. The honest limit: it depends on the documentation available, and a provider should be candid about when a site visit is warranted rather than treating "virtual" as always-appropriate.
3. Fixed-fee / software
Self-guided or software-assisted tools produce a report from owner-entered data, typically for smaller residential or simple properties with published flat pricing. Fast and cheap where they fit; not a substitute for an engineering study on a complex commercial building.
What "engineering-based" should mean
The IRS Cost Segregation Audit Techniques Guide describes the detailed engineering approach as the most rigorous. In practice, defensibility comes from the same things regardless of how the property was observed: components tied to identifiable functions and equipment, quantities supported by measurement or documentation, classifications supported by the tax authority, and honest treatment of the items that are genuinely judgment calls (structural-vs-removable, room-enclosure-vs-equipment). We reflect this in the rubric by weighting published methodology, a sample report and stated personnel — not marketing adjectives.
Where a site visit genuinely matters
Undocumented buildings, heavy or unusual specialty systems, disputes over what is structural, and situations where the taxpayer wants the maximum evidentiary record. Where the documentation is strong and the building is standard, the incremental value of a visit is smaller. The right answer is property-specific — which is why we treat delivery mode as one factor among seven, not a pass/fail.