In one paragraph
Cost Seg Smart and Engineered Tax Services (ETS) both produce IRS ATG-aligned engineered cost segregation studies using RSMeans construction cost data and MACRS classification per Rev. Proc. 87-56. ETS is a full-service specialty tax firm — cost segregation is one of several offerings alongside R&D tax credits, §179D energy deductions, transfer pricing, and other specialty tax services. ETS sends engineers on-site and runs a 4–8 week engagement, with residential cost-seg pricing typically starting around $5,000. Cost Seg Smart is cost-seg-only, automated, and built specifically for residential and small-commercial properties — studies start at $495 for residential under $300K basis and ship in under 60 minutes. ETS is the right call if you want one specialty-tax provider handling multiple workstreams (cost seg + R&D + §179D in a bundled engagement). Cost Seg Smart is the right call when you only need cost seg and want it fast and affordable.
At a glance: residential $500K STR comparison
| Dimension | Cost Seg Smart | ETS |
|---|---|---|
| Price (residential $500K) | $795 | ~$5,000+ typical |
| Turnaround | Under 1 hour | 4–8 weeks typical |
| Site visit | No (remote observation) | Yes (engineer on-site) |
| Methodology | RSMeans 2024 + MACRS | RSMeans + MACRS |
| Service scope | Cost seg only | Cost seg + R&D + §179D + transfer pricing |
| Form 3115 lookback | Included | Included |
| Best fit | Residential / STR / small MF / small commercial | Multi-credit specialty tax engagements, large commercial |
| Free revision policy | Yes, if your CPA can't use the report | Varies by engagement |
Methodology overlap (both firms)
The technical machinery is the same at both firms. Both use:
- RSMeans 2024 construction cost data — component-level $/SF basis with regional cost multipliers, calibrated to the property's market.
- MACRS classification per Rev. Proc. 87-56 — asset class lives that determine 5-, 7-, 15-, 27.5-, or 39-year recovery periods. Rev. Proc. 87-56 is incorporated into IRS Pub. 946 Appendix B.
- IRS Cost Segregation Audit Techniques Guide (Pub 5653) — the 13-element quality framework that defines what a defensible study contains. Both firms produce reports that address each element.
- Form 3115 §481(a) lookback support — for properties owned 2+ years without a prior cost-seg study, both firms produce the depreciation schedule the CPA files with the change-in-accounting-method election (DCN 7).
- Engineer attestation — both firms include a licensed engineer's attestation that the methodology was applied correctly.
Where Cost Seg Smart wins
- You only need cost seg. ETS's bundled-services pricing model presumes you want multiple specialty tax workstreams. If you just need a single property's cost segregation done, paying $5K+ for the engagement structure alone is overkill. Our $795 study produces the same defensible report.
- Residential rentals under $5M. A $400K SFR or STR can't justify a $5K ETS engagement. At our pricing, the same property generates real ROI on the study fee in Year 1 alone.
- STR portfolio owners. If you're running 5+ short-term rentals across markets, an automated workflow at our pricing scales linearly. Each property is a fresh order, fresh study, ~60 minutes; you don't need to schedule a different engineer visit per property.
- Speed-sensitive filings. If your CPA is filing your return next week and needs the schedule, our 60-minute turnaround beats ETS's 4–8 week engagement timeline.
- Form 3115 lookback on residential properties. The cumulative §481(a) catch-up on a 5-year-old $500K residential rental can easily exceed $30K–$50K. At our $1,295 study fee, the math works at any reasonable bracket. At ETS's pricing tier, the math requires high bracket and recent purchase to justify.
Where ETS wins
- You want a one-stop specialty-tax shop. If you're claiming R&D tax credits, §179D energy deductions, and cost seg for the same business, ETS's bundled engagement model is genuinely valuable. One project manager, one set of working papers, one audit defense relationship.
- Large commercial properties with energy upgrades. §179D requires energy modeling and certification — ETS does both alongside cost seg, so the basis allocations stay coordinated.
- R&D-credit-heavy businesses with rental real estate. Same one-vendor logic: if your business is already running R&D credit studies through ETS, adding cost seg as a related workstream makes operational sense.
- Properties where on-site engineering judgment matters. Specialty industrial, hospitality, ground-up commercial new construction over $5M — ETS's site-visit model captures details a remote pipeline could miss.
- Enterprise tax-prep workflows. Mid-market and large public companies running quarterly tax close cycles benefit from ETS's enterprise engagement structure. Our pipeline is built for individual real estate investors and small CPA practices.
How to decide
Three questions to ask:
- Do you need R&D credits, §179D, or other specialty tax services alongside cost seg? → ETS. The bundled engagement is the value.
- Is the property over $5M with significant energy upgrades, specialty assets, or hospitality build-out? → ETS.
- Otherwise (residential, STR, small MF, small commercial under $5M, cost seg only)? → Cost Seg Smart. Same methodology, dramatically lower study fee, faster turnaround.
If you want to see the math on a specific property before deciding, our free calculator gives a Year-1 estimate in 30 seconds. Full methodology details are at /methodology/, pricing tiers at /cheap-cost-segregation/.
For a side-by-side methodology comparison covering ETS and other specialty-tax firms, costsegregationreviews.com publishes provider-level reviews — useful as an editorial reference rather than a sales path.
Last reviewed: May 2026. Maintained by the Cost Seg Smart Editorial Team. Engineered Tax Services is the registered trademark of ETS Inc. No affiliation. This comparison is informational; both firms produce IRS ATG-aligned engineered cost segregation studies. Confirm pricing and scope directly with each vendor.