Read from the buildingSMART Clinic IFCs by scripts/build-reference-building.mjs: walls from the tessellated exterior-wall solids, glazing and doors per opening (windows and doors at OverallWidth × OverallHeight attributed to their host wall, exterior curtain walls at the projected outline of plates and mullions), roofs as each IfcRoof/IfcSlab ROOF element's one-sheet outer surface (EPDM 2,286.93 less the 74.55 under the standing-seam barrel, plus the barrels' 455.00), ground from the union of the slab-on-grade shadows a conditioned space stands on, volume from the IfcSpace rows (floor area × storey height, voids as their own solids).
A-CLIMATE · A Korean climate (Seoul) for a US building.
The IfcSite is the authoring tool's factory default (Boston) and the real location is redacted, so no climate may be taken from the file. ECO2 has no US regions. Any climate here is a substitution; this one is stated.
A-STUD-CAVITY · The 152 mm metal-stud cavity is UNFILLED.
The layer set names no insulation in it. Naming an R-13 batt would halve the wall U (0.404 → 0.218). A real clinic probably has one; the model does not say so, and the model is the source.
A-STEEL-BRIDGE · No thermal bridging through the steel studs or bar joists.
ISO 6946 Table 2 assumes an unsubdivided air layer; steel framing breaks that premise and the bridge is not represented. For steel it is tens of percent, not a rounding error, and is disclosed rather than tuned away.
A-SEAM-ROOF · The standing-seam roof's 286 mm bar-joist zone is an unventilated upward cavity (R 0.16), U 3.45.
No insulation layer exists in that assembly. As solid steel it would be 7.37. Both are stated; the cavity reading is used because a joist zone is mostly air.
A-SEAM-AREA · The standing-seam roof enters the engine at its one-sheet SURFACE, 455.00 m², and the 74.55 m² of EPDM deck under its low barrel enters at nothing.
Heat crosses the outer surface, and a pitched roof's surface exceeds its shadow by 1/cos(tilt) — the five barrels shadow 432.66 m² (384.44 as a union) and surface 455.00. The 382.28 this file carried as 'projected' until 2026-09-04 was neither the shadow nor the surface: it is 764.56 ÷ 2, where 764.56 is the sum of the faces within 26° of horizontal over BOTH sheets of a surface model wound upward twice — the near-horizontal part of one sheet with the steep flanks left out (manifest.areas.roofNote). The deck under the barrel is inside the envelope, so it is subtracted from the EPDM rather than priced twice.
A-ROOF-WEIGHT · One area-weighted roof U of 0.851 W/m²K.
The engine accepts a single roof U. Weighted by outer surface: EPDM 0.317 × 2,212.38 + standing seam 3.45 × 455.00, over 2,667.38. The standing seam is 17 % of the roof area and 69 % of its loss; the weighting is recorded so the constituents can be recovered.
A-GROUND-PAD · The 43.66 m² 'Floor:150mm Slab on Grade:221475' is not conditioned ground, and the slab area is 2,577.42 m² rather than 2,621.08.
It is an outdoor equipment pad beyond the wall line: no conditioned ground-storey space footprint overlaps its shadow and no IfcRelSpaceBoundary names it (manifest.groundSlabs[].excludedReason). It shares a family name with the two counted slabs, which is how it was counted until 2026-09-04. IsExternal was not consulted for any slab; the rule is whether a space stands on it.
A-SOIL · Soil conductivity 2.0 W/m·K under the slab.
ISO 13370's own default when soil is unknown. Soil moves the ground U from 0.188 (clay) to 0.380 (rock); 0.240 is the nominal.
A-GROUND-DT · The engine's 13.5 °C ground temperature and 4,380 h ground season.
ISO 13370's U pairs with annual-mean external air (~7.5 K at 20 °C indoor); the engine applies 6.5 K. About 13 % conservative, in the direction that makes the building look worse. Disclosed rather than reconciled, because reconciling moves every other building.
A-WWR-DENOMINATOR · WWR 0.1073 against GROSS wall area (opaque + glazing + doors), uniform across orientations.
The engine computes windows = gross × WWR and prices the rest as opaque wall, so the ratio must be quoted against the same gross the engine is handed, or the opaque wall silently loses 263 m². Derived from the two measured numbers, not typed. The per-orientation split is measured (manifest areas.glazingByOrientationSqm: N 54.79 / E 95.11 / S 49.58 / W 63.24) but the engine averages the four ratios against one gross wall, so per-sector ratios here would overstate the windows by 2.7 %; one ratio is applied and the split is shown, not consumed.
A-DOORS · The 36.08 m² of exterior door leaves are priced at the wall U-value.
The engine knows walls and windows and nothing between. Twelve leaves are flush insulated metal, so wall U is the nearer of the two; the thirteenth is the 4.19 m² 'Dbl Glass' entrance leaf in storefront #742, a glazed door counted as a door because the file types it IfcDoor — the one place this file departs from the verification transcript's 266.78, which counted that leaf as glazing. Leaving doors out would make the envelope smaller than the building.
A-WWR-LOW · 10.7–12.2 % is the building, not an undercount.
262.73 m² is reproduced element by element by scripts/lib/ifc-openings.mjs from the file — 58 windows at their frame opening, 15 exterior storefronts at the projected outline of plates and mullions — and reconciles with the earlier 267.16 / 266.78 to within the 4.19 m² entrance leaf now carried as a door. The 13 storefronts the file also marks IsExternal that were left out face a room on both sides (atrium screens and interior storefronts, 120.76 m²): IsExternal means 'not a partition' to the authoring tool, never 'faces outdoor air'. The two occupied storeys are ~7 % glazed and the concourse is daylit from above through clerestory monitors. Do not normalise upward.
A-GLAZING · Double low-e glazing, U 2.8, SHGC 0.40, thermal-break aluminium.
The IFC carries no IfcThermalTransmittance for its windows. Typical for a 2011 US commercial building; not read from the file.
A-AIRTIGHT · ACH50 = 5.
No blower-door result exists. A generic mid value for a 2011 commercial envelope; ACH50/20 is the engine's natural-infiltration divisor.
A-HVAC · Central gas heating (η 0.85), central chiller (COP 3.0), mechanical supply ventilation without heat recovery.
The HVAC IFC has 8 IfcFlowMovingDevice and 3 IfcEnergyConversionDevice, so system TYPE is partly stated, but efficiencies are not. These are placeholders to be replaced from the device data; they are not read from the file.
A-LPD · Lighting power density 9.4 W/m².
ASHRAE 90.1-2010 clinic allowance, 0.87 W/ft². The file states no lighting load.
A-OCCUPANCY · Clinic weekday/weekend schedules, 0.1 persons/m², 15 W/m² internal gain, 5 L/m²·day hot water.
No occupancy data exists in a coordination model. Generic clinic profile; every one of these is an assumption.
A-VOLUME · The ventilation term uses the gross conditioned volume (20,702 m³, inside the air barrier), not the 12,928 m³ the room solids sum to.
The file states no volume; both figures are measured from it. The room solids stop at 2.80 m ceilings under 4.57 m storeys, so their sum leaves out the plenums, and ACH50 is defined against everything inside the air barrier. Choosing the net figure would cut infiltration loss by 37 % for a building whose plenums are inside its envelope. Gross also includes the intermediate slab and structure (~0.3 m per storey, ~6 %), so it is slightly more than the air itself — well inside ACH50's own uncertainty, and stated rather than corrected.
A-ENVELOPE-SOURCE · Envelope areas come from the measured manifest, not from the recipe's footprint.
The recipe footprint is a 52.66 × 56.90 bounding box of an L-shaped plan; extruding it cannot reproduce a 240.73 m² clerestory. The measured areas travel on the recipe as `measuredEnvelope`, and `envelopeQuantities` returns them with source "measured" instead of extruding.