An Extensible GraphQL API for Fine-Grained Access to Building Information Models

Abstract: Building information exchange in large projects remains largely file-based, although many applications require only small, task-specific subsets of data. This paper addresses the need for element-level, transactional access to building information in web-based BIM workflows, including visualization and model analysis. While direct IFC-to-web mappings are technically feasible, they often result in complex schemas and verbose queries. We present a simplified GraphQL API that enables fine-grained access to building information while abstracting IFC complexity. Through atomic geometry resources, flattened property access, and a modular schema structure, the approach improves usability, query readability, and application-oriented BIM data access.