ONESTRUCTION fine-tunes Qwen3 into a construction-BIM foundation model using an open-source validator as the RL reward

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Published 2026-08-11, Ishigaki-IDS is built on Qwen3 in 8B/14B/32B sizes to author IDS (Information Delivery Specifications) XML files for BIM workflows. Because IDS was only published as a standard in 2024 and has almost no web corpus, the team leaned on expert-authored synthetic data through a three-stage pipeline — continued pre-training, supervised fine-tuning, then RLVR using buildingSMART's IDS-Audit-Tool directly as the reward function. On the team's IDS-Bench it scores near 100% on XML and IDS structural compliance and above 80% on content consistency, versus under 25% structural and near 0% content consistency for general models. Trained on two p5en.48xlarge H200 instances via AWS ParallelCluster with FSx for Lustre. The transferable pattern: when a domain has a deterministic validator, that validator is your reward model.