IFC 4.3.0.1 (IFC4X3) development

# 6.5.3.2 IfcCostItem

## 6.5.3.2.1 Semantic definition

An IfcCostItem describes a cost or financial value together with descriptive information that describes its context in a form that enables it to be used within a cost schedule. An IfcCostItem can be used to represent the cost of goods and services, the execution of works by a process, lifecycle cost and more.

Each instance of IfcCostItem may have a name and a description. Depending on the use for which the cost is intended, these values should be asserted on the basis of agreement. For instance, the Name attribute could be used to provide a common value that enables distinct instances to be brought together in a nesting arrangement (see below) while the Description attribute may be used to provide text used for item description in a costing schedule.

An IfcCostItem can link one or many IfcCostValue's representing a unit cost, total cost, or a unit cost with one or many quantities used to generate the total cost. The quantities can be given as individual quantities, or those quantities are provided as element quantities by one or many building elements. The IfcCostValue.Category attribute indicates the category of cost, which may be used to present the value in a particular column. For nested cost items (having IfcRelNests relationship), IfcCostValue.Category is significant such that IfcCostValue.AppliedValue is calculated as the sum of all nested costs having the same IfcCostValue.Category or if set to an asterisk ('*'), then the sum of all nested costs of all cost types. An IfcCostValue may represent an original value or a value derived from formulas using IfcAppliedValueRelationship. For example, taxes may be calculated as a percentage of a subtotal.

## 6.5.3.2.5 Formal representation

ENTITY IfcCostItem
SUBTYPE OF (IfcControl);
PredefinedType : OPTIONAL IfcCostItemTypeEnum;
CostValues : OPTIONAL LIST [1:?] OF IfcCostValue;
CostQuantities : OPTIONAL LIST [1:?] OF IfcPhysicalQuantity;
END_ENTITY;