The aim of this Quantity Take-Off Information Delivery Manual is specifying how quantities of individual entities like spaces, walls, coverings and valves are stored and exchanged between parties in the lifecycle of a facility
according to the IFC4 structure.
The Information Delivery Manual (IDM) serves two use cases that both are related to adding quantity
take-off information to objects stored in the IFC4 structure. Quantities are used in many business cases,
e.g. cost estimation, life cycle costing, life cycle assessment, logistics, purchasing, maintenance, energy
analysis and calculation of sustainable performance. Objects like spaces, walls, coverings and valves are
often designed and modelled in BIM-tools by one type of professionals, while other types of professionals
need the quantities from the objects as input to perform their services. In both situations, the use cases
are depending on access to information about quantities.
The first use case is based on using the exiting IFC4 Based quantities. The second use case is related to
the business case that exceeds the capacity of Base quantities and requires adding additional Custom
quantities to the objects