As-built model

An as-built model is the digital model of an asset as it was actually constructed, rather than as it was originally designed. It records the final geometry and installed condition of the building at a point in time — including the field changes, substitutions and tolerances that real construction always introduces.

That is the key distinction from the as-designed model. As-designed expresses the design intent and drives construction; as-built documents the finished result for everything that comes after. The two answer different questions: one says what should be built, the other records what was. (The looser term as-is is used for the current state of an existing asset, designed or not.)

As-built models are typically produced by scan to BIM — converting a point cloud into modelled elements — then verified in the field against the captured reality before the record is issued. The level of fidelity is high (broadly the old LOD 400–500 territory). At handover it gives the owner a reliable digital record, and in operation it underpins maintenance, refurbishment and asset management; under ISO 19650 it feeds the operational asset information model. In Italian practice it is the modello as-built.