Comparison · residential

KBKG vs. Cost Seg Smart — Residential cost segregation, side by side.

In one paragraph

KBKG and Cost Seg Smart both produce residential cost segregation studies using the same methodology — RSMeans 2024 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, engineer-attested, 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.

At a glance: residential cost segregation, $500K STR comparison

Dimension Cost Seg Smart KBKG
Price (residential $500K)$795~$5,000+
TurnaroundUnder 1 hour4–6 weeks typical
Site visitNo (remote observation)Yes (engineer on-site)
MethodologyRSMeans 2024 + MACRSRSMeans + MACRS
Audit defenseEngineer attestation + free CPA responseEngineer attestation + audit support package
Form 3115 lookbackIncludedIncluded
Best fitResidential / STR / small MF / small commercial under $5M$5M+ commercial, hospitality, REIT
Free revision policyYes, if your CPA can't use the reportVaries 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.

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 RSMeans classification matters. We score it the same way KBKG would; it costs $795–$1,295 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:

  1. Is the property over $5M with unusual specialty assets, hospitality, or ground-up commercial? → KBKG.
  2. Do you need site-visit-level engineering judgment for a property with unusual construction not visible in public data? → KBKG.
  3. 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.

Frequently asked

What is KBKG Residential Cost Segregator and how is it different from KBKG's full-service studies?

KBKG Residential Cost Segregator is KBKG's DIY software product, priced around $499 per property — a separate offering from their full-service engineered studies that start around $5,000. The DIY tool gives you access to KBKG's component library and depreciation schedule generator, but you do the data entry, classification confirmation, and report assembly yourself — typically 2–4 hours of customer labor per property. The full-service KBKG engagement includes an on-site engineer visit, custom report drafting, and project management. At the same ~$495 price point as the DIY tool, Cost Seg Smart's automated studies are done-for-you with engineer attestation, a CPA-Ready Guarantee, and 60-minute turnaround — same methodology, no customer labor required. For a detailed DIY-vs-automated comparison see /compare/vs-diy-software/.

Is KBKG legitimate?

Yes. KBKG is one of the largest and most established traditional cost segregation firms in the US, founded in 1999, with offices in multiple cities and a strong reputation in commercial cost-seg work. Their reports are IRS ATG-aligned, engineer-attested, and widely accepted by CPA firms and the IRS. The comparison here is not a quality knock on KBKG — it's a fit comparison. KBKG's labor model is built for $5M+ commercial properties; Cost Seg Smart's is built for residential and small-commercial under $5M. Both produce defensible studies in their respective lanes.

How is Cost Seg Smart different from KBKG methodologically?

Methodologically, the two firms are similar: RSMeans 2024 cost data, MACRS classification per Rev. Proc. 87-56, IRS Cost Segregation Audit Techniques Guide framework, engineer attestation. Where they differ is the data inputs and labor model. KBKG sends a licensed engineer to the property for an on-site walkthrough and uses their first-hand observations alongside RSMeans data. Cost Seg Smart works from county assessor records, satellite imagery, structured property data (RentCast, OSM, BLS PPI), and the same RSMeans cost library. For typical residential and small-commercial properties, the resulting classification falls within a few percentage points of an in-person engineering study; for unusual construction or properties with significant non-public renovations, on-site judgment can materially affect the schedule and KBKG is the better fit.

When should I use KBKG instead of Cost Seg Smart?

Three scenarios: (1) commercial properties over $5M with unusual specialty assets — hospitality, healthcare, ground-up new construction, manufacturing with custom MEP. (2) Properties with significant recent renovations not visible in public data, where on-site engineering will catch components a remote pipeline could miss. (3) REIT-scale portfolios where you're running dozens of $20M+ properties under one tax-prep workflow that needs enterprise audit-support packaging. For everything else — residential, STR, small multifamily, small commercial under $5M — Cost Seg Smart's $495–$1,895 tier produces the same defensible result KBKG would, faster and at a fraction of the cost.

Can my CPA accept either firm's report?

Yes, in nearly all cases. Both firms produce 40+ page CPA-ready PDFs with depreciation schedules, MACRS classification per component, Form 3115 §481(a) sections for lookback studies, and engineer attestation. Most CPAs care about report contents, not vendor brand. Cost Seg Smart additionally offers a CPA-Ready Guarantee — if your CPA flags a format or documentation issue, we'll revise at no charge. If we can't resolve the issue, you get a full refund.

Why is the price so different if the methodology is the same?

Most of a $5,000 KBKG study fee is project-managed labor: discovery call, scheduling, on-site engineer visit (travel, time, write-up), manual cost-database lookups, hand-built schedule, custom report drafting from scratch. The labor model is the bottleneck — not the methodology. The methodology (RSMeans + MACRS + IRS ATG) is public and unchanged. Cost Seg Smart applies that same methodology to standardized, structured property data so the deterministic 90% of the workflow runs in seconds, with engineer review concentrated on outliers. Same defensible deliverable, dramatically lower delivery cost. For commercial properties where on-site judgment materially affects accuracy, KBKG's labor model is genuinely worth what it costs; for residential and small-commercial properties, the labor isn't necessary for the methodology to work.

Ready to act on this?

Estimate your year-1 benefit.

Free calculator. No signup. From $495 if you proceed.

Estimate my savings Order my study