ifcpropertyptemplatedefinition是所有属性和属性集模板的泛化。模板定义项目中使用的各个属性的集合、类型、名称、适用的度量值类型和单位。属性模板定义可以是：
■属性集模板-IfcPropertySetTemplate，一组属性模板，用于确定在项目上下文中使用的属性的定义。
■属性模板-ifcpropertyptemplate，一个确定在同一项目上下文中使用的特定属性定义的模板。模板可以确定基于该模板的每个属性的名称、描述、数据类型、单位或标准表达式。
ifcpropertyptemplatedefinition的子类型是在项目上下文中声明的。最上面的模板定义（例如，包含多个IfcPropertyTemplate的IfcPropertySetTemplate）应使用继承的HasContext inverse属性与上下文（IfcProject或IfcProjectLibrary）相关。
在IFC4中增加的新实体。
| # | Attribute | Type | Cardinality | Description | C |
|---|---|---|---|---|---|
| IfcRoot | |||||
| 1 | GlobalId | IfcGloballyUniqueId | [1:1] | Assignment of a globally unique identifier within the entire software world. | X |
| 2 | OwnerHistory | IfcOwnerHistory | [0:1] | Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object,
NOTE only the last modification in stored - either as addition, deletion or modification. |
X |
| 3 | Name | IfcLabel | [0:1] | Optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule. | X |
| 4 | Description | IfcText | [0:1] | Optional description, provided for exchanging informative comments. | X |
| IfcPropertyDefinition | |||||
| HasContext | IfcRelDeclares @RelatedDefinitions |
S[0:1] | X | ||
| HasAssociations | IfcRelAssociates @RelatedObjects |
S[0:?] | 引用ifcreassociates之间的关系，从而引用那些与属性定义关联的外部定义的概念，如分类、文档或库信息。 | X | |