Level of Development is the single most common source of scope disputes in outsourced BIM work. Everyone nods at LOD 350 in the kick-off call, and three weeks later one party expected fabrication-ready connections while the other modelled generic assemblies.
Agree it per category, not per project
A project is not one LOD. Walls might be 350 because they drive the permit set, while furniture stays at 100 because nobody is building from it. We write the LOD down per element category before modelling starts and attach it to the scope document.
What each level buys you
LOD 100 is massing — volume, orientation and area only. It is enough to test a planning envelope and nothing more.
LOD 200 gives generic placeholders with approximate size and location. Good for coordination, not for pricing.
LOD 300 is where most permit documentation lives: specific assemblies, accurate dimensions, real quantities.
LOD 350 adds the interfaces between systems — the connections and penetrations that clash detection depends on.
LOD 400 is fabrication detail. Expensive, and only worth it where something is genuinely being made from the model.
The practical rule
Model to the level your next decision needs, and no further. Over-modelling is the most expensive habit in BIM because it feels like progress.