Carbon Index — EC3 Material Mapper, EPD Linking & Scope Reconciliation
The EC3 Material Mapper is the material resolution and specification alignment engine of the Carbon Index application. It bridges the gap between raw BIM authoring properties (Revit materials, IFC property sets, Bentley MicroStation attributes) and certified Environmental Product Declarations (EPDs) from Building Transparency EC3 and the University of Bath Inventory of Carbon and Energy (ICE v3) database.
Material Mapper Workspace Layout
The Material Mapper provides comprehensive tools to review, match, and override material definitions across all BIM elements:
- Mapping Quality & Source Summary Bar: Instant counts of Verified EC3 EPDs, ICE Benchmarks, Heuristic Fuzzy Matches, Unlinked Items, and Excluded Scope.
- Search & Filter Controls: Filter by material match status (
MATCHED,MANUAL_OVERRIDE,UNLINKED,IGNORED), resolution source (EC3_LIVE_EPD,ICE_V3_BENCHMARK), or text search. - Class Mapping Accordion Cards: Grouped by EC Class or Category, showing overall match confidence and material assignments.
- Interactive Action Buttons:
Live EC3 EPD Search: Query 100,000+ verified digital EPDs.Apply CI Benchmark: Assign standardized ICE v3 industry baseline factors.Exclude Scope: Mark non-physical/non-structural elements as excluded ($0\ kgCO_2e$).Bind Quantity Property: Map authoring quantity parameters directly from the iModel schema.
Material Matching Tier Hierarchy
Carbon Index employs a strict 4-tier resolution hierarchy to guarantee high data integrity:
| Tier | Source Name | Description | Match Confidence |
|---|---|---|---|
| Tier 1 | EC3_LIVE_EPD / MANUAL_OVERRIDE |
Specific product-level EPD selected via Building Transparency EC3 or user override with verified manufacturer data. | 100% |
| Tier 2 | ICE_V3_BENCHMARK |
Standardized UK/EU canonical industry average material benchmark from the University of Bath ICE Database v3.0. | 85% – 95% |
| Tier 3 | HEURISTIC_FUZZY |
Rule-based regex pattern match resolving raw BIM string variations (e.g. Conc_C30/37_Ext → Concrete, C30/37). |
70% – 85% |
| Tier 4 | UNLINKED |
Material string cannot be reliably matched to an approved carbon profile; flagged for human review. | 0% |
| Excluded | IGNORED |
Non-carbon or non-physical items (e.g. IfcSpace, SpatialLocation, ZoneBoundary) excluded from statutory scope. |
N/A |
Live EC3 EPD Search & Assignment Dialog
Clicking Override Material or EC3 EPD Search opens the Carbon Material Override Dialog:
EC3 Search & Selection Features:
- Real-Time EC3 Query: Search by product name, manufacturer, masterformat category, or EPD ID.
- EPD Data Grid:
- Product Name & Manufacturer: Verified manufacturer and trade brand.
- Global Warming Potential (GWP): $A1–A3$ embodied carbon factor expressed per declared unit (e.g. $kgCO_2e/m^3$ or $kgCO_2e/kg$).
- Data Quality Indicators: EPD expiry date, geographic location (plant location), third-party verifier (e.g. UL, IBU, EPD Australasia).
- Direct EPD Link: Clickable OpenXPD URL to inspect the full statutory certificate on BuildingTransparency.org.
- Scope Application:
- Apply override to the single selected element.
- Apply override to all elements sharing the same class / material pattern across the entire iModel.
Canonical ICE Material Benchmarks
For elements where a manufacturer-specific EPD is not yet procured (e.g. early design stages or Concept Gateways), Carbon Index provides over 30 pre-configured Carbon Index (CI) Canonical Benchmarks:
| Material Category | Canonical Name | Density ($kg/m^3$) | $A1–A3$ Factor ($kgCO_2e/kg$) | Cradle-to-Grave ($A–C$) |
|---|---|---|---|---|
| Concrete | Ready-mix Concrete C25/30 | 2,350 | 0.115 | 0.132 |
| Concrete | Ready-mix Concrete C30/37 | 2,400 | 0.134 | 0.151 |
| Concrete | Precast Concrete Hollowcore | 2,450 | 0.160 | 0.178 |
| Metals | Structural Steel (Heavy Sections) | 7,850 | 1.550 | 1.620 |
| Metals | Reinforcement Steel (Rebar) | 7,850 | 1.990 | 2.050 |
| Timber | Cross Laminated Timber (CLT) | 500 | -0.750 (biogenic) | 0.420 |
| Timber | Glulam (Glued Laminated Timber) | 550 | -0.680 (biogenic) | 0.460 |
| Masonry | Standard Facing Brickwork | 1,700 | 0.220 | 0.245 |
| Glass | Double Glazed Sealed Unit | 2,500 | 1.450 | 1.580 |
| Insulation | Mineral Wool Insulation Board | 35 | 1.250 | 1.340 |
Class Quantity Bindings & Schema Parameter Mapping
Where BIM models contain author-prescribed geometric parameters (e.g. StructuralFraming.NetVolume or Slab.GrossArea), users can bind these properties directly to the calculation engine:
- Click Bind Quantity on any EC Class card.
- The system executes a live ECSQL introspection to discover all numeric geometric properties available on that class.
- Select the target property (e.g.
GeometricParams.Volume) and its physical unit ($m^3, m^2, m, kg$). - The calculation engine reconciles mass ($Mass = Volume \times Density$) using the prescribed author parameter.