IFC Checker and BIM Validation

The IFC (Industry Foundation Classes) is an open data format, not controlled by a single operator, created to allow interoperability between the various building process stakeholders. It aims to promote and facilitate model information exchangeability without loss or distortion of data or information.

It contains information of various types (geometric data, properties, relationships with other objects).

The IFC tree-structure represents the tree structure of the IFC model where the hierarchy of elements classified on the basis of the IFC Type is shown.

In practice, it contains all the elements that characterise the model (entity types, objects, instances, etc.).

Its organisation can be summarised as follows:

• IFCProject
• IFCSite (construction site)
• IFCBuilding (building)
• IFCBuildingstorey (first floor, second floor, etc.)
• IFCBuildingelements (wall, window, floor, etc.).

The IFCTypeObject represents a class that contains properties common to a set of homogeneous entities (i.e. entities that belong to the same class), e.g. all walls that have certain common characteristics.

There is also the ObjectType, which is a specific attribute.

An example of an "IFCtypeObject" is the "IFCWallType" which includes all walls.

IFC entities are: "classes of information defined by common attributes and constraints". (ISO 10303-11). They are objects uniquely defined in the IFC model that can be assigned certain attributes and dependencies with other elements of the model. Examples of IFC entities are walls, windows, pillars, etc.

The "IFC Entities" are made up of a geometric part and an information part. The latter, in turn, can be subdivided into properties and relationships between the various elements in the model.

IfcPropertySet is the set of all properties that can be assigned to an object in an IFC model.

The properties contained in such a set can be of two types:

• predefined
• additional/customised (i.e. user-defined).

Checking an IFC model means analysing the properties of the various entities and making sure that they meet certain requirements (for example, checking that all selected walls have a certain thermal transmittance value).

In this respect, an IFC model checker tool is needed to enable 'intelligent' filters and specific property controls.

This may involve designers, BIM Specialists, BIM Coordinators and BIM Managers who need to assign, verify or remove certain characteristics of the IFC model, or contracting authority operators (public bodies/consultants) responsible for checking delivered projects.

usBIM.checker checks all entity-related properties from 'smart' object selections.

usBIM.checker is very useful for the verification phase of an IFC model, in summary it can:

• verify the existence of properties of objects
• view and check property values
• verify the correctness of values
• generate and export property control templates
• insert, modify and delete properties
• generate a consistency report between the properties and the values contained in the IFC file

With usBIM.checker you can define the following conditions:

• At least - enables the IFC model to be granted 'at least' the properties that are listed in the spaces provided.
• Only - allows you to determine "only" those properties that must be present in the IFC model
• Verification - allows you to check whether the properties that have been identified in the spaces provided are present in the IFC model.
• Delete - this function gives the possibility to delete the properties present in the model (in this case there is no possibility to use a selection filter as in the previous cases)

usBIM.checker is an IFC file checker designed to solve the problems of checking, inserting and deleting properties.

It can greatly simplify all those operations that would be much more cumbersome and complex with a typical BIM authoring.

Yes, with usBIM.checker you can export your template for use in another project (the template is separate from the model).

With these templates, you can take advantage of the same selection and control filters on several templates and optimise the verification operations.

You can easily create a template by selecting appropriate filters (object selection criteria), identifying attributes, PsetNames, properties, etc., and specifying the properties to be inserted or checked (checks to be made on properties).