LoopLedger

Open specification · Built environment

Every asset leaves the building with its record.

LoopLedger is an open specification for material passports and recovery evidence. A passport stays with each fixture, panel and chair through every owner. It records how the item came apart and where it went, signed by both parties at every handoff.

Review the schema Read the spec
Passport · example fixture
booth-seat · 2-seat module
revision
G5 · screwed joints
carrier
GS1 Digital Link QR
owner
tenant → reseller
  1. removedmethod, labor, cause
  2. processedseparated at joints
  3. weighedfractions by material
  4. record_transferredsigned by both
  5. disposition_finalresale

Routing

Disposal is the last rung

Before demolition starts, each asset is routed down a fixed ladder. Explicit, versioned rules pick the destination, and every routing decision cites the rule version that governed it.

  1. redeploy
  2. remanufacture
  3. resale
  4. donate
  5. recycle
  6. disposal

Append-only passports

Identity, components, composition, condition and custody. Built on GS1 EPCIS 2.0 events, so nothing is overwritten and nothing is backfilled.

Two-party custody

Every handoff is signed by both sender and receiver, with photos, scale tickets and manifests. Diversion figures come from weighed, signed events, never from self-reported totals.

Jurisdiction rules as code

Local requirements become versioned rules that limit where each asset can go at each site.

Feedback to design

Recovery outcomes are measured for each design revision and each joint. The results flow back to manufacturers, and to IFC and bSDD for the design tools.

The drill

Which revision came apart better, and why?

The repository includes a synthetic drill. One catalog item in two revisions runs through removal, separation and weighing. The drill compares results within a life band, so the older revision's age isn't counted against its joints.

Revision G4

Bonded upholstery. Deliberately older assets in the fixture set.

Revision G5

Mechanically fastened. The bonded joint should account for the difference.

Alignment

Built on existing standards

Where an open standard already exists, LoopLedger uses it instead of inventing a rival format.

Status

Phase 0, under review

Each phase starts only after the previous gate passes. The current gate is an external review of the passport schema.

Done

Schema v0.1

JSON-LD passport and event schemas, with a validation suite.

Done

Vocabularies v0.1

Joint type, material and cause, mapped to bSDD classes where they exist.

Open

G0 review

Reviewers from EPCIS/UNTP, BIM/design data and EPD/LCA practice. Read the brief.

Next

Phase 1

One real recovery event run end to end, producing a verified diversion report.