In one paragraph
KBKG and Cost Seg Smart both produce residential cost segregation studies using the same methodology, industry-standard 2026 construction cost data, MACRS classification per Rev. Proc. 87-56, IRS ATG-aligned documentation. KBKG's full-service residential engagement sends an engineer on-site, takes 4–6 weeks, and starts around $5,000. KBKG also offers a DIY software product (KBKG Residential Cost Segregator) at ~$499 with 2–4 hours of customer labor. Cost Seg Smart's automated residential studies work from satellite imagery, county assessor records, and structured property data, done for you, with internal technical review & QC, delivered in under 1 hour, starting at $495 for residential under $300K basis. KBKG is the right call for $5M+ commercial, hospitality, REIT-scale portfolios, and properties with unusual specialty assets. Cost Seg Smart is the right call for residential rentals, STR, small multifamily, and small commercial under $5M.
Disclosure: Cost Seg Smart operates this comparison and is one of the firms compared here. See the methodology page for our standalone documentation.
KBKG Residential Cost Segregation: Overview
KBKG offers residential cost segregation through two products: a full-service engagement that sends an engineer on-site (4–6 week turnaround, starting around $5,000) and a DIY software product called KBKG Residential Cost Segregator (~$499 with 2–4 hours of customer labor to complete the inputs and review the output). Both products use the same construction-cost-database methodology and Rev. Proc. 87-56 MACRS classification framework that Cost Seg Smart uses. The differences are price, turnaround, and labor model — not methodology.
At a glance: residential cost segregation, $500K STR comparison
| Dimension | Cost Seg Smart | KBKG |
|---|---|---|
| Price (residential $500K) | $795 | ~$5,000+ |
| Turnaround | Under 1 hour | 4–6 weeks typical |
| Site visit | No (remote observation) | Yes (engineer on-site) |
| Methodology | industry-standard 2026 construction cost data + MACRS | construction cost data + MACRS |
| Audit defense | Internal technical review & QC + free CPA response | Engineer attestation + audit support package |
| Form 3115 lookback | Included | Included |
| Best fit | Residential / STR / small MF / small commercial under $5M | $5M+ commercial, hospitality, REIT |
| 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:
- industry-standard 2026 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, KBKG includes a licensed engineer's attestation; Cost Seg Smart includes internal technical review & QC confirming the methodology was applied correctly.
This is what reassures buyers and tax professionals: the deliverable from a $795 Cost Seg Smart study and a $5,000 KBKG study addresses the same IRS quality framework using the same cost basis. Where they differ is the labor model, not the engineering.
Where Cost Seg Smart wins
- Residential rentals under $5M. A $400K SFR or STR can't justify a $5,000 KBKG study fee, the math thins out fast. At $795, a $400K STR with 27% reclassification produces ~$32,000 in Year-1 federal savings at 37%. Same defensible report; one of them produces ROI, the other doesn't.
- Small multifamily and 2–4-unit properties. Same dynamic. A $1.45M North Park fourplex generates around $76,762 in Year-1 federal savings on a $1,395 study at our pricing. KBKG's labor model doesn't fit this segment; ours does.
- STR owners on event-driven properties. Pacific Beach, Old Town Scottsdale, East Austin, Joshua Tree, high FF&E density (pool equipment, outdoor kitchens, themed furnishings) is exactly the case where engineering-grade cost-data classification matters. We score it the same way KBKG would; it costs $795–$1,495 instead of $5,000+.
- Form 3115 lookback on residential portfolios. A 5-year-old $500K rental can yield $30K–$50K of cumulative missed depreciation as a §481(a) catch-up. The economics work at our price point regardless of bracket; at KBKG's price point you need a high bracket and recent purchase to justify.
- Speed-sensitive filings. If your CPA needs the schedule for a return that's already in extension, our 60-minute turnaround vs. KBKG's 4–6 weeks is the deciding factor.
Where KBKG wins
- Commercial properties over $5M. Hospitality (hotels, resorts), large multifamily over 100 units, ground-up commercial new construction, and properties with significant specialty assets (manufacturing equipment, healthcare specialty fixtures) benefit from on-site engineering judgment. KBKG's site-visit model adds material accuracy at this scale.
- REIT-scale portfolios. If you're managing dozens of $20M+ properties under one tax-prep workflow, KBKG's enterprise engagement model and audit-support packages are built for that scale.
- Properties with significant recent renovations. If your $3M property had a $400K renovation last year that isn't fully reflected in public data (no permit pulls, no assessor update), an on-site engineer will catch components our remote pipeline could miss.
- You specifically expect IRS examination. Both firms produce ATG-aligned, audit-defensible reports. If you want maximum defense-in-depth (extra exhibits, expanded methodology section, dedicated audit-response retainer), KBKG's larger engagement model accommodates that.
- You're a CPA firm with an enterprise client base. KBKG's CPA partner program is mature. Cost Seg Smart's CPA portal is newer and best-suited to small-to-mid-tier CPA practices.
If you've already worked with KBKG
Many of our customers have. The most common pattern: KBKG handled their large commercial property well, and now they want a study on a follow-on residential or small-commercial property in the portfolio. At a $5,000+ KBKG fee on a $400K rental, the math thins out, the study fee starts to consume the Year-1 benefit. Same engagement at our $795 price point preserves the math while keeping the methodology consistent. We're not a replacement for KBKG on the properties they're built for; we're the right fit for the long tail of residential properties their pricing model can't serve.
How to decide
Three questions to ask:
- Is the property over $5M with unusual specialty assets, hospitality, or ground-up commercial? → KBKG.
- Do you need site-visit-level engineering judgment for a property with unusual construction not visible in public data? → KBKG.
- Otherwise (residential, STR, small MF, small commercial under $5M, follow-on portfolio properties)? → 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/, and pricing tiers at /cheap-cost-segregation/.
For a wider view across the market, costsegregationreviews.com publishes how different firms approach engineering studies, useful as an editorial reference rather than a sales path.
Last reviewed: May 2026. Maintained by the Cost Seg Smart Editorial Team. KBKG is the registered trademark of KBKG, 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.