Project information

[shamimhasan07]

We have prepared a series of articles in which we will look at how to prepare a model for examination using the example of using Renga and Revit software products.
Content

Working with custom properties
Changing object types during export
Setting up IFC4 export
Mapping
Error log
At the moment, passing the state examination in the BIM format is mandatory. The requirements for the CIM undergoing the state examination are formed by the state bodies themselves, taking into account the specifics of work in their region. And here a problem arises: the requirements of different examinations for the composition of the CIM differ.

That is why we have prepared a series of two articles in which we will look at how to prepare a model for examination using the example of using Renga and Revit software products.

However, first, let us note some similarities among the requirements established for passing the examination.

Firstly, the model must be presented in IFC format version 4.0 and higher. However, the requirements apply only to models of social buildings:

Administrative and business facilities
Apartment buildings
Outpatient and polyclinic institutions
Educational institutions
The requirements for the composition of attributes, grouping of attributes by corresponding sets of properties, naming of attributes, data types and filling of values ​​are also described in sufficient detail. Although the set of attributes and filling of elements differ.

Thirdly, when passing the state examination, it is necessary to create a basic model, which should indicate the construction volumes of the above-ground and underground parts and place zones for functional zoning and calculation of the main OKP. Thus, designers must fill the CIM with entities with data on the project itself:

General information
Main characteristics
Required indicators of a capital construction project
Technical and economic indicators of the project
Climatic and geotechnical data, etc.
Finally, we note one more requirement - the absence of collisions between model elements. This point was also taken into account when developing the functionality of the Renga system for export to IFC.

Let us now move on to the main topic of the article and consider the requirements that must be met when preparing the CIM for state examination.

Why is the detailing of the CIM of an object so important in project management?

Project information
As we have already noted, the model must contain data about the project. For this purpose, the following entities were added to Renga:

Project (class IfcProject)
Plot (class IfcSite)
Building (class IfcBuilding)
You can access them through the "Style Management" menu. The menu options are divided into three tabs for each entity separately. In addition, you can add any number of custom properties to these entities, entering all the information necessary for the examination.

Working with custom properties
Many people want the project assessment to be automated. This requires that all model data be interpreted correctly. To achieve this, each model attribute must be assigned a specific data type.

With this in mind, Renga has expanded the list of data types that users can use. The previously existing types have been expanded to include "String" and "Real Number":

With a wide range of types at your fingertips, you won't have any problems interpreting your model data when exporting to third-party programs.

Now let's briefly describe working with custom properties, which is done in the "Object Properties" menu. When we create a new custom property, we must assign it the correct data type.

How to prepare CIM for examination
Properties can be assigned to both object instances and object styles. Once properties have been added to a project and assigned to the appropriate object types, they will need to be populated.

Renga has enough functionality to speed up this complex, attention-demanding process as much as possible. You can select objects that are identical by brand, type or style via the context menu and specification. The specification can also be used to select by any similar custom properties.

Changing object types during export
Since the information model is considered in the IFC format, all model objects must be exported in accordance with the corresponding classes described in IFC. The standard representation of the IFC4 RV-1.2 model, according to which the requirements of the state examination are formed, describes 16 classes of architectural elements of the building, 12 classes of structural elements, 65 classes of elements of internal engineering systems and another 18 classes of elements, which include, for example, the phone number italy previously mentioned class "Building" (Ifc Building). In total, there are more than 100 classes!

How can you avoid getting confused when modeling and meet all the requirements? In fact, it's simple - model as you like.

According to the requirements, the floor covering should be uploaded to IFC under the Ifc Covering class, and the external curtain wall façade under the Ifc Curtain Wall class. Renga does not have these classes yet, and they are not needed to transfer the condition assessment. Floors can be modeled separately, and the external façade as a second wall with its own layers of construction. In general, you can redefine the type of objects.

To do this, you will need to add the following custom properties to the model objects:

Ifc EntityType: required to override the entity type
Ifс ObjectType: set only if the predefined type USER DEFINED is specified in the object instance properties
Ifc ElementType: Set only if you set the predefined type USER DEFINED in the object style properties
These three properties in IFC define the element type according to the class definition and describe this class. They are mandatory for overriding, and if values ​​are assigned to them, the objects are exported under the new class and type.

Type redefinition is a very powerful tool. But to use it confidently, you just need to understand the description of IFC classes. The IFC reference will help you with this.