5.4.3.1 IfcBuilding

	Bâtiment
	Gebäude

A building represents a structure that provides shelter for its occupants or contents and stands in one place. The building is also used to provide a basic element within the spatial structure hierarchy for the components of a building project (together with site, storey, and space).

NOTE  Definition from ISO 6707-1:
Construction work that has the provision of shelter for its occupants or contents as one of its main purpose and is normally designed to stand permanently in one place.

A building is (if specified) associated to a site. A building may span over several connected or disconnected buildings. Therefore building complex provides for a collection of buildings included in a site. A building can also be decomposed in (vertical) parts, where each part defines a building section. This is defined by the composition type attribute of the supertype IfcSpatialStructureElements which is interpreted as follow:

• COMPLEX: building complex
• ELEMENT: building
• PARTIAL: building section

The IfcBuilding is used to build the spatial structure of a building (that serves as the primary project breakdown and is required to be hierarchical). The spatial structure elements are linked together by using the objectified relationship IfcRelAggregates.

HISTORY  New entity in IFC1.0.

Figure 82 shows the IfcBuilding as part of the spatial structure. It also serves as the spatial container for building and other elements.

NOTE  Detailed requirements on mandatory element containment and placement structure relationships are given in view definitions and implementer agreements.

Figure 82 — Building composition

Systems, such as building service or electrical distribution systems, zonal systems, or structural analysis systems, relate to IfcBuilding by using the objectified relationship IfcRelServicesBuildings.

Attribute Use Definition

Figure 83 describes the heights and elevations of the IfcBuilding. It is used to provide the height above sea level of the project height datum for this building, that is, the internal height 0.00. The height 0.00 is often used as a building internal reference height and equal to the floor finish level of the ground floor.

• base elevation of building provided by: IfcBuilding.ElevationOfRefHeight, it is usually the top of construction slab
• base elevation of terrain at the perimeter of the building provided by: IfcBuilding.ElevationOfTerrain, it is usually the minimum elevation is sloped terrain
• total height of building, also referred to as ridge height (top of roof structure, e.g the ridge against terrain): provided by BaseQuantity with Name="TotalHeight"
• eaves height of building (base of roof structure, e.g the eaves against terrain): provided by BaseQuantity with Name="EavesHeight"

Figure 83 — Building elevations

Plumbing System Design

 Instance diagram

The Identity concept applies to this entity.

Exchange
Import			R						-
Export	R	R	R	R	R	R	R	R	-		R	R	R

The Classification concept applies to this entity as shown in Table 13.

Source Name Tokens Description CSI OmniClass 11-00 00 00 Construction Entities By Function

Table 13 — IfcBuilding Classification

Classification is required to determine the required plumbing fixtures per occupant.

Exchange
Import									-
Export	R	R		R	R	R	R	R	-		R	R	R

Properties for Occurrences

The Properties for Occurrences concept applies to this entity as shown in Table 14.

PredefinedType Name   Pset_BuildingCommon

Table 14 — IfcBuilding Properties for Occurrences

Exchange
Import									-
Export	O	O		O	O	O	O	O	-		O	O	O

Product Assignment

The Product Assignment concept applies to this entity as shown in Table 15.

Type Description IfcTask Tasks assigned to building in early design indicating occupancy considerations, where tasks may have assigned product resources to indicate required plumbing fixtures.

Table 15 — IfcBuilding Product Assignment

Exchange
Import
Export	R

Spatial Decomposition

The Spatial Decomposition concept applies to this entity as shown in Table 16.

Spatial Parts IfcBuildingStorey

Table 16 — IfcBuilding Spatial Decomposition

Exchange
Import			R						-
Export	O	O	R	R	R	R	R	R	-		R	R	R

Building Location

The Building Location concept applies to this entity.

The building elevation must be known to determine pressure requirements for connected utilities.

Exchange
Import									-
Export	O	R		O	R	O	O	O	-		O	O	R

XSD Specification:

EXPRESS Specification:

Attribute Definitions:

Inheritance Graph:

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