In smart home projects, building data management at the design stage increasingly relies on digital-twin assets delivered via game engines. Without a clear governance workflow, however, these practices tend to generate non-standard building data on the consumption side, causing broken data chains and increasing construction and management risks. To address this problem, this study proposes a traceability-oriented governance workflow that strengthens IfcGUID compliance and automatically detects and converts inconsistent digital-twin assets into IFC-compliant, auditable data, thereby reducing data chain breakage and improving cross-system traceability in building data management. The workflow uses IfcGUID as a cross-system primary key and is evaluated in a virtual smart home project through a pre-test–repair–post-test experiment at the design stage. We examine four indicators of IfcGUID quality—completeness, validity, uniqueness, and stability—together with a bridge recognition rate that reflects game engine interoperability on the consumption side. The results show that all four IfcGUID indicators converge towards 1 after applying the workflow, and the bridge recognition rate approaches 100%, indicating that the risk of data chain breakage, measured on an IFC basis, is substantially reduced. Within existing toolchains, this workflow provides design teams, visualization teams, clients, and auditors with a low-cost and reproducible path for standardizing design-stage digital-twin assets and establishing a traceable, auditable baseline for cross-system interoperability and lifecycle building data management and data reuse.

This study addresses non-standard data that emerge on the consumption side when digital-twin assets are introduced during the design stage of a smart home. We present a traceability-oriented governance workflow that standardizes non-standard assets into compliant, auditable data streams for cross-system reconciliation in building data management. The workflow front-loads control, measurement, and evidence: the export/consumption pipeline is frozen; Industry Foundation Classes Globally Unique Identifier (IfcGUID) compliance is enforced by adopting the Industry Foundation Classes (IFC) Globally Unique Identifier (IfcGUID-22) as the minimal cross-system object key; containers and objects are registered in a controlled Common Data Environment (CDE); and Unity unique identifiers are bridged to IfcGUID-22 via a template-based mapping with read-only minimal repairs to restore traceability and game engine interoperability. Effectiveness is validated in a virtual testbed using a pre-test → bridging/minimal-repair → post-test design under a fixed denominator, interpreter, and configuration. Four IfcGUID metrics—completeness, validity, uniqueness, and stability—are computed together with an Ifc-side stability control; interoperability is summarized by Bridge Recognition Rate (BRR) and Disconnect Rate (DR). Results show BRR = 0.9987 with 1/778 broken pairs and 18 stable scene recognitions; completeness, validity, and stability reach 1.00, and uniqueness improves to 0.976744. The findings demonstrate a verifiable, low-cost, and transferable path that reduces breakage risks from non-standard data and restores cross-system traceability for Building Information Modeling (BIM) managers, CDE managers, visualization/engine teams, and owners.