Quantity take off (QTO)
Deriving measured quantities of materials and elements directly from the model.
Quantity take off (QTO) is the measurement of how much of each material or element a project contains — areas, volumes, lengths, counts — derived directly from the model rather than read off drawings by hand. Because the objects already carry geometry and properties, the model can report consistent quantities far faster, and far less error-prone, than manual measurement.
The real benefit is not just speed but synchronisation. When a design changes, a model-based take off can be re-run so quantities reflect the current state, instead of drifting out of date the moment a drawing is revised. Good take off depends on disciplined modelling — correct object types, classification and a fit-for-purpose level of information — so that what is counted is actually what will be built.
Quantity take off is the measured base that 5D cost work is built on: quantities first, then rates and estimating logic on top. In Italian practice it underpins the computo metrico / estrazione delle quantità from the model.
Need this in practice?
Quantity Take Off →