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Sample studies Timber Ridge at Sea Ranch Audit trail

Audit trail. Every classification, sourced.

Concrete proof of methodology for IRS audit defense. CPA-only view. Never included in client deliverable.

Internal — not in client deliverable

Engine run identity

Hash-locked, content-addressable. Same inputs → same outputs, byte-identical. Re-running this study produces the same hash.

engine_run_id
3a7e9b2c-4d51-4e8a-9f0c-1b8d2e4f6a92
content_hash (SHA-256)
a4f8b2e7d9c1f3a5b8e2d4f7c1a3b5e8d2f4c7a1b3e5d8f2c4a7b1e3d5f8c2a4
runTimestamp
2026-05-20 14:32:18 PDT
engine_version
v1.0.0-beta1
study_id
STD-2026-05-0042
firm_id
FRM-Smith-Tax-Co (Smith Tax Co.)
cpa_user_id
USR-Sarah-Chen (Sarah Chen, Engagement Lead)
data_quality_score
94 / 100 — all required fields provided + assessor printout uploaded

Defensibility audit. 5 rules.

Synchronous post-engine audit. Every rule must pass before delivery. Defensibility score 92/100 — HIGH confidence.

1
Citation coverage
Every classification cites a library entry. 47 components, 47 citations, 0 orphans.
PASS
2
Bonus rate defensibility
100% bonus applied per PIS 2025-06-15 (post-OBBBA Jan 19, 2025 restoration).
PASS
3
Math consistency
5-YR + 15-YR + 27.5-YR = $1,050,000 depreciable basis. Reconciliation Δ = $0.00 (within ±5% threshold).
PASS
4
State schedule pattern
California Pattern 2 — full decoupling. State schedule = MACRS without bonus. Verified per FTB SB 711 conformity to Jan 1, 2025.
PASS
5
Provenance trace
Every dollar amount traces to CPA-entered input or citation library reference. SourcedFact chain complete.
PASS

Classified components. Per-component rationale.

47 components, each with classification, citation, cost, and confidence score.

Kitchen cabinetry — built-in custom millwork
CLASS: 27.5-YR Residential · CITE: RP-87-56-class-275-residential · CONF: HIGH
HIGH $34,000
Kitchen appliances (refrigerator, range, dishwasher, microwave)
CLASS: 5-YR Personal Property · CITE: RP-87-56-class-5yr-personal · WHITECO test passes (movability, function) · CONF: HIGH
HIGH $18,500
Removable cabinetry — guest bath vanities
CLASS: 5-YR Personal Property · CITE: RP-87-56-class-5yr-personal · CONF: MEDIUM (verify removable)
MEDIUM $12,200
Driveway + pathways (concrete)
CLASS: 15-YR Land Improvement · CITE: RP-87-56-class-15yr-landimp · CONF: HIGH
HIGH $28,400
Hot tub — built-in (in-ground spa)
CLASS: 15-YR Land Improvement · CITE: RP-87-56-class-15yr-landimp · WHITECO test (annexation, time) · CONF: HIGH
HIGH $22,000
Landscaping — irrigation system + plantings
CLASS: 15-YR Land Improvement · CITE: RP-87-56-class-15yr-landimp · CONF: HIGH
HIGH $19,800
HVAC — central system (furnace + condensers + ductwork)
CLASS: 27.5-YR Residential · CITE: RP-87-56-class-275-residential · HCA precedent (structural integration) · CONF: HIGH
HIGH $48,000
Building structure (foundation, framing, roof, walls)
CLASS: 27.5-YR Residential · CITE: RP-87-56-class-275-residential · CONF: HIGH
HIGH $626,800
+ 39 more components View full classified list

PlatformEvent timeline

Every material action on this study, append-only. 7-year retention.

14:32:18
ENGINE_RUN_COMPLETED
Engine M1-M6 completed; 47 components classified.
Actor: ENGINE_SYSTEM · Severity: INFO
2026-05-20
14:31:55
DEFENSIBILITY_AUDIT_PASSED
All 5 audit rules passed; score 92/100 HIGH.
Actor: ENGINE_SYSTEM · Severity: INFO
2026-05-20
14:28:12
REVIEW_COMPLETED
Engineer review: 5 rules pass; 2 MEDIUM-confidence flags reviewed and accepted.
Actor: AI_ENGINEER (auto-approved at HIGH overall) · Severity: INFO
2026-05-20
14:22:04
STUDY_INPUTS_CONFIRMED
CPA confirmed property facts. Land allocation Tier 1 from assessor (20%).
Actor: Sarah Chen (USR-Sarah-Chen) · Severity: INFO
2026-05-20
14:18:33
DOCUMENT_UPLOADED
Sonoma County assessor printout uploaded (sonoma-assessor-timber-ridge.pdf, 2.4MB).
Actor: Max Boucher (client portal) · Severity: INFO
2026-05-20
View full event log (42 events)