Charleston, SC · $580K
Original 1990s triplex
Year-1 federal benefit
$29,200
Triplex
Triplex cost segregation: $48K–$120K Year-1 deductions.
The triplex is the duplex's better-yielding cousin — three sets of kitchens, bathrooms, HVAC, water heaters compress into a tighter footprint and a denser 5-yr bucket.
The 30-second answer
Triplex cost segregation is an engineering-based study that reclassifies a three-unit rental's components out of the default 27.5-year residential schedule into faster 5- and 15-year MACRS classes. A triplex reclassifies in line with other small residential — typically 15–19% of building basis — because three sets of kitchens, bathrooms, HVAC systems, and water heaters compress into one building and form a dense 5-year bucket, on top of the shared parking, landscaping, and site work. With 100% bonus depreciation the reclassified amount is deductible in Year 1; the loss is passive under IRC §469 unless you qualify as a real estate professional or materially participate.
Triplex cost segregation reclassifies 15–19% of depreciable basis from the 27.5- or 39-year shell into 5-, 7-, and 15-year MACRS classes per 26 U.S.C. § 168 and Rev. Proc. 87-56. Under OBBBA's permanent 100% bonus depreciation (placed-in-service 2025+), reclassified components are deductible in year one. All credible cost-seg providers use the same federal framework — industry-standard 2026 construction cost data, MACRS classification, IRS Audit Techniques Guide (Pub 5653) compliance. What differs across property types is land-allocation share, FF&E weight, and material-participation eligibility under §469.
| Property type | Reclass to 5/7/15-yr | Year-1 federal benefit | Study cost |
|---|---|---|---|
| STR | 23–29% | $55K–$205K | From $495 |
| SFR | 15–20% | $30K–$100K | From $495 |
| Condo | 11–17% | $17K–$61K | From $495 |
| Duplex | 14–19% | $33K–$98K | From $795 |
| Fourplex | 17–21% | $68K–$165K | From $795 |
| Office | 17–21% | $100K–$535K | From $1,995 |
| Retail | 21–27% | $105K–$570K | From $1,995 |
| Industrial | 16–20% | $95K–$680K | From $2,495 |
| Self-storage | 20–26% | $170K–$1.3M | From $2,495 |
| Medical office | 16–23% | $95K–$485K | From $2,495 |
| Mixed-use | 12–19% | $71K–$480K | From $1,995 |
| Multifamily | 15–21% | $48K–$150K | From $795 |
| Multifamily 5+ | 15–20% | $120K–$800K | From $1,995 |
| Triplex this page | 15–19% | $48K–$120K | From $795 |
| Restaurant | 16–24% | $81K–$405K | From $2,495 |
| Vet | 20–26% | $100K–$440K | From $2,495 |
| Gym | 19–35% | $110K–$890K | From $2,495 |
| Dealership | 26–36% | $550K–$3.6M | From $2,495 |
| ADU | 7–12% | $8K–$33K | From $495 |
| Commercial | 18–27% | $105K–$685K | From $1,995 |
| Data center | 45–60% | $3.0M–$31M | $4,995–$54,995 (sub-$100M); $100M+ by proposal |
| Senior living | 20–30% | $340K–$2.0M | By proposal |
Reclassification ranges from internal benchmarks across 4,000+ studies; Year-1 federal benefit assumes 37% bracket and full first-year usability. Study costs are Cost Seg Smart pricing — comparable engineering studies elsewhere range $5,000–$15,000+. See full provider comparison.
Real examples
What triplex cost seg looks like in practice.
Estimates assume 37% federal bracket and full first-year usability of the loss (active income offset or REPS). Your actual benefit varies with bracket, basis allocation, and CPA's treatment.
Good fit when…
- ✓Pure-rental triplexes
- ✓House-hackers with rental-side basis allocation
Skip it when…
- ×Triplex with shared utilities (lower reclassification)
Estimate
Run the numbers on your triplex.
Pre-set to Triplex defaults — adjust price + bracket to match your property.
Estimated Year-1 tax savings · Click to order →
$26,640
on $72,000 of accelerated deductions
Want this in writing for your CPA? Get a 1-page analysis →5-yr15-yr27.5/39-yr
Study cost
$995
ROI on study
27×
Delivery
< 1 hour
Estimate based on industry-standard 2026 construction cost data and IRC §168(k). Your actual result varies with property age, condition, and basis allocation.
Frequently asked
Triplex cost segregation, by question.
Do triplexes qualify for cost segregation?
Yes, and they reclassify high for residential — typically 15–19% of basis — because three sets of kitchens, baths, HVAC, and water heaters form a dense 5-year bucket, plus the parking and site work. The whole reclassified amount is deductible in Year 1 under 100% bonus depreciation.
Is a triplex better than a duplex for cost segregation?
Usually a bit, yes. A triplex adds a third set of unit fixtures into one building, so the 5-year personal-property share is denser — typically 15–19% versus 15–19% for a duplex. The lookback math is also strong if you've owned it a few years.
How much does a triplex cost segregation study cost?
Triplexes are priced on the multifamily 2–4 tier: from $795 for a sub-$300K property, $995 for $300K–$700K, and $1,095 up to $1M, delivered as a CPA-ready PDF in under an hour.
Regulation references
The rules that govern triplex cost segregation.
- Real estate professional status (REPS) — the 750-hour and 51% tests under 26 U.S.C. § 469(c)(7), and the seven material participation tests under Treas. Reg. § 1.469-5T. Required to offset W-2 income with long-term rental losses unless the property qualifies under the STR loophole.
- Form 3115 (catch-up depreciation) — how to apply cost segregation to a property placed in service in a prior year. Full § 481(a) catch-up adjustment, automatic change-number 7, no IRS user fee.
- Treas. Reg. § 1.469-1T — full reference — all six (A)–(F) exceptions that reclassify a rental as non-rental for passive activity loss purposes.
- Regulations hub — full canonical reference for all cost segregation regulations.
- irsdepreciationrules.com — companion plain-language reference for the underlying IRS depreciation statutes (operated by Cost Seg Smart).
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