BIM

BIM's substance is the shift from drawing documents to modelling objects: a wall or a pump in a BIM workflow is not lines but an object with properties — type, material, rating, relationships — from which drawings, schedules and quantities are derived views. Around the models sits the collaboration machinery: a common data environment where versions and statuses are managed, exchange formats for moving models between tools, and information requirements defining what data each party owes at each stage.

Its promise is single-source truth: quantities taken from the model, coordination performed in it, and a data-rich asset handed to operations. Its delivery depends on the unglamorous parts — naming conventions, information requirements, model management — far more than on the software.

The gap between the two has names. "Lonely BIM": modelling for one party's efficiency with no shared data flow. Models built as geometry with empty attributes, from which no take-off can be trusted. And the dual-truth problem — where drawings remain the contractual deliverable, maintained separately from the model until they disagree, at which point the project discovers it never decided which one governs.