Model Building

Overview

Provides the information concerning buildings within a basic building model.
A building represents a structure that provides shelter for its occupants or contents and stands in one place. The building is an element within the spatial structure hierarchy for the components of a building project (together with site, storey, and space).
A building is (if specified) associated to a site. It is therefore a requirement that, before a building can be specified, a site must exist. Refer to the functional part fp_site for further information
A building may span over several connected or disconnected buildings. To allow for this, a 'building complex' can be defined which comprises several elemental buildings.
Similarly, a building can also be broken down into several identifiable parts or sections. To allow for this, a 'building part' can be defined such that an elemental building comprises several building parts.
The information presented in this functional part is sufficient for the exchange of a basic building model. This information includes:

Specify the site on which the building is contained
Specification of building name and description if required
An extended name for the building may also be specified if required
Dimensional information about the building may be given to enable the creation of a shape representation if the building shape cannot otherwise be found from the building elements (wall, roof etc.) from which the building is constructed. This would be particularly the case during early stages of design where the building mass needs to be established but the building itself is not broken down into parts. Overall building shape might also be provided for communication with geographic information systems. The form of shape representation used for a building may differ at various stages of a building project and these are specifically identified within exchange requirements. Particular forms of shape representation may include
- 2D footprint representation with additional height information given as a quantity
- 3D body representation
The length, width and height dimensions of the building may be established by the bounding box shape representation
Specification of whether the building concerned is a complex of several buildings, an elemental (single) building or a part of a building.
Where the building is a 'complex', identification of the elemental buildings that are nested into the complex.
Where the building is a 'part', identification of the building into which the part is nested
It should be noted that the 'part' breakdown of a building may give rise to parts that overlap in terms of their shape content. Therefore, the overall shape of a building should not be derived by adding together the shapes of parts.
The reference elevation above sea level of the building may be given. This provides a reference height from which the elevation of individual building storeys and other elements in a building may be determined (where the reference height is considered to be 0.0 for measurement purposes). The reference height is usually specified as being at the ground floor level of a building or the level at which the main entrance to the building is located.
The reference elevation above sea level of the terrain around the building may be given. This provides a reference height for the surrounding site that can be used for measurement purposes. Note that this may be used in conjunction with the reference elevation of the building for calculation purposes referring to a datum point.
The postal address for the building may be given.
The occupancy type of the building may be given according to the local/national building codes to specify the use or purpose of the building (and therefore how it will be assessed for building codes, fire codes etc. and what design parameters may need to be later applied).

Results

Model of building occurrence(s) including shape representation and other basic information

Description	Entity/Pset/Functional Part	MAN	REC	OPT
Specify the site on which the building is contained	fp_contains_in_spatial_structure[site, Unknown macro: {building} ]
A building is directly specified as an occurrence. It does not have a defining type entity.
Set the global unique identifier	IfcBuilding.GlobalId::IfcGloballyUniqueId
Apply the owner history	IfcBuilding.OwnerHistory::fp_apply_owner_history
Specify the name of the building	IfcBuilding.Name::IfcLabel
Specify a description for the building	IfcBuilding.Description::IfcText
Specify an extended name for the building if required	IfcBuilding.LongName::IfcLabel
Establish the placement of the origin point of the building	IfcBuilding.ObjectPlacement::fp_place_object
If the shape representation of the building cannot be defined by the elements used in its construction, define its shape representation _* Note that a building may have several representations._	IfcBuilding.Representation::fp_represent_product
Set the composition type of the building occurrence (complex, element or part)	IfcBuilding.CompositionType::IfcElementCompositionEnum
If the composition of the building is a 'complex', identify the elemental buildings that form part of the complex	fp_nest[building]
If the composition of the building is a 'part', identify the elemental building of which it forms a part	fp_nest[building]
Any elements that are to be contained within the building should be identified	fp_contains_in_spatial_structure[building, Unknown macro: {elements} ]
Specify location parameters for the building
Specify the postal address for the building	IfcBuilding.BuildingAddress::fp_address
Specify the elevation above sea level of the reference height for the building. Elevation of the reference height should be measured above sea level. This is the reference height used for all storey elevation measures. It defines the datum height which is typically set to 0.0 for measurement of other heights in the building. It is usually the ground floor level.	IfcBuilding.ElevationOfRefHeight::IfcLengthMeasure
Specify the elevation above the minimal terrain level around the foot print of the building. Elevation of the terrain should be measured above sea level.	IfcBuilding.ElevationOfTerrain::IfcLengthMeasure
Define properties for the building
Identify the occupancy type (purpose group) of the building	Pset_BuildingCommon.OccupancyType::IfcLabel
Define the common property set for the building	fp_define_by_properties
Define quantities for the building A range of quantities is foreseen as being required for the building. Actual quantities required are defined in exchange requirements	fp_define_quantity

IFC Entities Required

IfcBuilding
IfcElement
IfcObject
IfcProduct
IfcRoot
IfcSpatialStructureElement

IFC Datatypes Required

IfcElementCompositionEnum
IfcGloballyUniqueId
IfcLabel
IfcLengthMeasure
IfcText

IFC Functions Required

-

IFC Property Sets Required

Pset_BuildingCommon

IDM Functional Parts Required

fp_address
fp_apply_owner_history
fp_contains_in_spatial_structure
fp_define_by_properties
fp_define_quantity
fp_nest
fp_place_object
fp_represent_product

EXPRESS-G

EXPRESS Schema

SCHEMA FP_MODEL_BUILDING;

  TYPE IfcGloballyUniqueId = STRING (22) FIXED;
  END_TYPE;

  TYPE IfcLabel = STRING;
  END_TYPE;

  TYPE IfcLengthMeasure = REAL;
  END_TYPE;

  TYPE IfcText = STRING;
  END_TYPE;

  TYPE IfcElementCompositionEnum = ENUMERATION OF
    (COMPLEX,
     ELEMENT,
     PARTIAL);
  END_TYPE;

  ENTITY IfcProduct
    ABSTRACT SUPERTYPE
    SUBTYPE OF(IfcObject);
      ObjectPlacement : OPTIONAL fp_place_object;
      Representation  : OPTIONAL fp_represent_product;
    WHERE
      WR1 : (EXISTS(Representation) AND EXISTS(ObjectPlacement))
            OR (EXISTS(Representation) AND 
            (NOT('IFC2X2_FINAL.IFCPRODUCTDEFINITIONSHAPE' IN TYPEOF(Representation))))
            OR (NOT(EXISTS(Representation)));
  END_ENTITY;

  ENTITY IfcObject
    ABSTRACT SUPERTYPE
    SUBTYPE OF(IfcRoot);
      ObjectType : OPTIONAL IfcLabel;
    WHERE
      WR1 : SIZEOF(QUERY(temp <* IsDefinedBy | 'IFC2X2_FINAL.IFCRELDEFINESBYTYPE' IN TYPEOF(temp))) <= 1;
  END_ENTITY;

  ENTITY IfcRoot
    ABSTRACT SUPERTYPE;
      GlobalId     : IfcGloballyUniqueId;
      Name         : OPTIONAL IfcLabel;
      Description  : OPTIONAL IfcText;
      OwnerHistory : fp_apply_owner_history;
    UNIQUE
      UR1 : GlobalId;
  END_ENTITY;

  ENTITY IfcSpatialStructureElement
    ABSTRACT SUPERTYPE
    SUBTYPE OF(IfcProduct);
      LongName        : OPTIONAL IfcLabel;
      CompositionType : IfcElementCompositionEnum;
    WHERE
      WR41 : (HIINDEX(SELF\IfcObject.Decomposes) = 1) 
             AND
             ('IFC2X2_FINAL.IFCRELAGGREGATES' IN TYPEOF(SELF\IfcObject.Decomposes[1])) 
             AND
             (('IFC2X2_FINAL.IFCPROJECT' IN TYPEOF (SELF\IfcObject.Decomposes[1].RelatingObject)) OR
             ('IFC2X2_FINAL.IFCSPATIALSTRUCTUREELEMENT' IN TYPEOF (SELF\IfcObject.Decomposes[1].RelatingObject))
             );
  END_ENTITY;

  ENTITY IfcBuilding
    SUBTYPE OF(IfcSpatialStructureElement);
      ElevationOfRefHeight : OPTIONAL IfcLengthMeasure;
      ElevationOfTerrain   : OPTIONAL IfcLengthMeasure;
      BuildingAddress      : OPTIONAL fp_address;
  END_ENTITY;

  ENTITY fp_address;
  END_ENTITY;

  ENTITY fp_apply_owner_history;
  END_ENTITY;

  ENTITY fp_place_object;
  END_ENTITY;

  ENTITY fp_represent_product;
  END_ENTITY;

  ENTITY fp_nests;
  END_ENTITY;

  ENTITY fp_define_quantity;
  END_ENTITY;

  ENTITY fp_contains_in_spatial_structure;
  END_ENTITY;

  ENTITY fp_define_by_properties;
  END_ENTITY;

END_SCHEMA;

Page Operations

Browse Space