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SampleHouse Analysis — Ifc4_SampleHouse Guardrails

Foundation: BBC · DATA_MODEL · BIM_COBOL · MANIFESTO · TestArchitecture

58 elements, one storey — the hello-world proof. Smallest Rosetta Stone validates the full pipeline end-to-end with ARC + STR + CW disciplines.

Stone: 1 of 3 (smallest — hello-world proof) Updated: 2026-03-28 (S100-p85 fleet audit recompilation)


Building Identity

Property Value
Name Ifc4_SampleHouse
IFC version IFC4 (single file)
Country N/A (reference building)
Type Single-storey residential
Elements 58
Disciplines 3 (ARC: 35, STR: 20, CW: 3)
M_Product_Category RE (Residential)
Prefix SH
C_DocType_ID RE_SH
Reference DB DAGCompiler/lib/input/Ifc4_SampleHouse_extracted.db
BOM DB library/SH_BOM.db

Discipline Breakdown (verified against component_library.db)

Discipline Count Elements
ARC 35 Walls, doors, windows, furniture, slabs, coverings
STR 20 Slabs, walls (structural)
CW 3 Cold water pipes
Total 58

Key Settings

Setting Value Source
Compilation mode EN-BLOC (singularity) BBC.md §3.3
BOM tree shape Self-describing (BBC.md §1): BUILDING → FLOOR → ROOM → SET → LEAF for SH RE pattern
Origin convention BUILDING has world LBD; FLOOR/ROOM zeroed (R16) BBC.md §4.1
YAML classify_sh.yaml Single storey, 5 rooms
Mirror None (single unit)
Scope spaces floor_rooms: IFC space → BOM template mapping classify_sh.yaml

Gate Status

Gate Status Value
G1-COUNT PASS 58
G2-VOLUME PASS +0.00%
G3-DIGEST PASS 496022db
G4-TAMPER PASS 0 violations / 20 rules
G5-PROVENANCE PASS 7 checks
G6-ISOLATION PASS

Recompilation (S100-p85 Fleet Audit, 2026-03-28)

BOM walk recompilation via CompileStagewriteFromBomWalk(). 7/7 PASS.

Metric Value
Elements 58 (was 55 — 3 additional from CW discipline)
Root BOM BUILDING_SH_STD, origin=(-9.235, -2.746, -0.470)
Verbs 22 PLACE, 4 CLUSTER
Disciplines ARC=24, STR=2, CW=2
LOD binding 58 LOD, 0 fallback, 0 missing
H6 WARNs 24 (MEP schedule vs actual — no MEP elements yet)

LMP Drift Check: 6 pass, 0 fail, 2 deferred

§ Check Verdict
§1 Input=Output PASS (58/58)
§2 LOD400 PASS (58/58 OK, 0 warn, 0 fail)
§3 Compiler Only PASS (T18/T19/T20 guard)
§6 Output Path PASS (single path)
§7 Separate From Input PASS (bom.db=library/_SH_compile.db)
§8 Visual Fidelity PASS (geometry OK)
§4 Openings deferred (no proof aggregate)
§9 Orientation deferred (no proof aggregate)

Guardrails

  1. Smallest stone — any regression shows here first. Run SH before DX/TE.
  2. BOM walk path — single compilation path for all buildings (S100-p72).
  3. TRIM verb active — glass curtain wall panels trimmed to the pitched roof intersection. SH now uses 22 PLACE + 4 CLUSTER verbs. CLUSTER factorizes windows.
  4. ProveStage skipped — no relational data (§4, §9 deferred).

Known Issues

  • H6 WARNs (24): MEP schedule expects products in rooms but no MEP elements compiled yet. These are advisory findings in LOG mode — will resolve when discipline recipes produce elements.
  • ProveStage 0ms: Prover skipped for all non-relational buildings. Not SH-specific.

SH is the hello-world proof. If SH breaks, nothing else can be trusted. See BOMBasedCompilation.md §3.3 (EN-BLOC = HelloWorld).