In one paragraph
Cost Seg Smart and Engineered Tax Services (ETS) both produce IRS ATG-aligned engineered cost segregation studies using industry-standard 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, §45L credits and other specialty tax services. ETS includes an on-site property inspection and publishes a typical timeline of 4–6 weeks from start to finish; on pricing, ETS publishes a $3,000–$12,000 range depending on property size and complexity (not a residential-specific figure). 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 are usually delivered the next business day. 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.
Disclosure: Cost Seg Smart operates this comparison and is one of the firms compared here. See the methodology page for our standalone documentation.
Cost Seg Smart in brief
- Cost Seg Smart is an engineered cost segregation provider for residential, short-term-rental, multifamily and commercial property, with residential studies from $495 and commercial from $1,995.
- Cost Seg Smart delivers most residential studies the next business day, remotely, using remote observation together with industry-standard 2026 construction cost data.
- Cost Seg Smart classifies components under MACRS per Rev. Proc. 87-56 and documents every study against the 13 quality elements of the IRS Cost Segregation Audit Techniques Guide (Pub 5653), including Form 3115 §481(a) catch-up schedules for properties owned two or more years.
- Cost Seg Smart prices a sub-$300K residential study at $495 and delivers it usually by the next business day; Engineered Tax Services publishes a $3,000–$12,000 range across property types and a typical 4–6 week timeline.
At a glance: residential $500K STR comparison
| Dimension | Cost Seg Smart | ETS |
|---|---|---|
| Price (residential $500K) | $895 | $3,000–$12,000 published range (all property types; no residential price published) |
| Turnaround | Usually the next business day | 4–6 weeks typical (per ETS) |
| Site visit | No (remote observation) | Yes (on-site property inspection) |
| Methodology | industry-standard 2026 construction cost data + MACRS | construction cost data + MACRS |
| Service scope | Cost seg only | Cost seg + R&D + §179D + §45L + other specialty services |
| 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 | Not published; ask ETS |
Methodology overlap (both firms)
Both firms describe an engineering-based approach aligned with the IRS Audit Techniques Guide. The shared framework:
- 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).
- Reviewed deliverable — ETS describes itself as a licensed engineering firm and lists an engineering analysis report, component-level cost detail and audit-ready documentation; Cost Seg Smart includes internal technical review & QC confirming the methodology was applied correctly.
Where Cost Seg Smart wins
- You only need cost seg. ETS is built as a multi-service specialty tax firm. If you just need a single property's cost segregation done, a study priced in ETS's published $3,000–$12,000 range is more than a small residential property needs. Our $895 study produces the same defensible report.
- Residential rentals under $5M. A $400K SFR or STR is a hard fit for a study priced in the thousands. 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 and a fresh study, usually delivered the next business day; 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 next-business-day turnaround in most cases beats the 4–6 week timeline ETS publishes.
- 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, a review site we operate, publishes provider-level reviews.
Last reviewed: September 22, 2026. ETS pricing, timeline and services are as published on engineeredtaxservices.com on 2026-09-22. Maintained by the Cost Seg Smart Editorial Team. Engineered Tax Services is a trademark of its owner. Cost Seg Smart has no affiliation with Engineered Tax Services. This comparison is informational; both firms produce IRS ATG-aligned engineered cost segregation studies. Confirm pricing and scope directly with each vendor.