IfcEnvironmentalImpactValue

Definition from IAI: An IfcEnvironmentalImpactValue is an amount or measure of an environmental impact or a value that affects an amount or measure of an environmental impact.

> HISTORY: New entity in IFC 2x2

### Use Definitions

The IfcEnvironmentalImpactValue contains the value of the environmental impact. For example this could represent the volume of carbon dioxide emission, amount of operational energy or mass of aluminum used in a product.

Each instance of IfcEnvironmentalImpactValue may also have an ImpactType. There are many possible types of environmental impact value that may be identified. To allow for any type of environmental impact value, the IfcLabel datatype is assigned. The following defines some impact types that might be applied:

CO2 emission
Embodied energy
Mass of aluminium
Operational energy
Resource
Water pollution

Where a formal standard is not used, it is recommended that local agreements should be made to define allowable and understandable impact value types within a project or region.

EXPRESS specification:

ENTITY IfcEnvironmentalImpactValue
SUBTYPE OF ( | IfcAppliedValue);
ImpactType | : | IfcLabel;
Category | : | IfcEnvironmentalImpactCategoryEnum;
UserDefinedCategory | : | OPTIONAL IfcLabel;
WHERE
WR1 | : | (Category <> IfcEnvironmentalImpactCategoryEnum.USERDEFINED) OR ((Category = IfcEnvironmentalImpactCategoryEnum.USERDEFINED) AND EXISTS(SELF\IfcEnvironmentalImpactValue.UserDefinedCategory));
END_ENTITY;

Attribute definitions:

ImpactType | : | Specification of the environmental impact type to be referenced.
Category | : | The category into which the environmental impact value falls.
UserDefinedCategory | : | A user defined value category into which the environmental impact value falls.

Formal Propositions:

WR1 | : | The attribute UserDefinedCategory must be asserted when the value of the IfcEnvironmentalImpactCategoryEnum is set to USERDEFINED.

Inheritance graph

ENTITY IfcEnvironmentalImpactValue;
ENTITY IfcAppliedValue;
Name | : | OPTIONAL IfcLabel;
Description | : | OPTIONAL IfcText;
AppliedValue | : | OPTIONAL IfcAppliedValueSelect;
UnitBasis | : | OPTIONAL IfcMeasureWithUnit;
ApplicableDate | : | OPTIONAL IfcDateTimeSelect;
FixedUntilDate | : | OPTIONAL IfcDateTimeSelect;
INVERSE
ValuesReferenced | : | SET OF IfcReferencesValueDocument FOR ReferencingValues;
ValueOfComponents | : | SET OF IfcAppliedValueRelationship FOR ComponentOfTotal;
IsComponentIn | : | SET OF IfcAppliedValueRelationship FOR Components;
ENTITY IfcEnvironmentalImpactValue;
ImpactType | : | IfcLabel;
Category | : | IfcEnvironmentalImpactCategoryEnum;
UserDefinedCategory | : | OPTIONAL IfcLabel;
END_ENTITY;