**2. Method**

BIM is recognized as the most effective platform for information exchange on building projects in the construction industry. It supports the development of various software. It facilitates automated or semi-automated ACCC of the building projects for compliance with building regulations and standards for the participants (designer, architect, engineer, contractor, owner, etc.) involved in the building production process. The data of the building project are represented in two ways in the ACCC [12]. These are:


### **2.1 BIM model**

Building Information Modeling (BIM) is a simulation prototyping technology. The definition of the BIM and BIM model according to the US National BIM Standard is "BIM is the digital representation of the physical and functional characteristics of a building project. The BIM model is a reliable source of information where information is shared from conceptual design to demolition of the building project throughout the building project life cycle [13]." BIM, one of the most critical developments in the construction industry, emerges as a technology that enables the management of the building project data in a digital environment by incorporating different tools and

*The Data Representations of a Building Project: BIM Model, and IFC or IFCXML Data Standard DOI: http://dx.doi.org/10.5772/intechopen.104580*

processes into the building design. It is based on the building elements that form the building project. It models the relationships of the building elements with each other. Supporting interdisciplinary integration in the construction industry, BIM effectively changes its role in building design and construction by creating a database of the building elements used throughout the building project life cycle [14, 15].

#### **2.2 IFC data standard**

Industry Foundation Classes (IFC) data standard, a new industry foundation class for interoperability, was created by the Industry Alliance for Interoperability (IAI) in 1997 [16]. IFC is an object-oriented data standard developed in the EXPRESS language, and it is independent of any software [17]. IFC is supported by BIM-based software. Therefore, it is accepted that BIM and IFC data standards will significantly advance and facilitate cooperation in the building design process. IFC provides users with comprehensive information and features about the building project. It also represents international standardized object definitions [18]. Objects are also named as the building elements in the building project. The most important feature of the IFC data standard is its rich data structure that allows a building element to be defined by more than one feature. The IFC standard data is divided into different building elements such as the wall, column, beam, floor, window, door, railing, elevator, stair, etc. These building elements have a three-dimensional geometry and parameters, which can be divided into size, material, property, price, quantity, etc.

#### **2.3 IFCXML data standard**

IFCXML is a language defined in XML, equivalent to the EXPRESS-based specification of IFC data. The implementation of the IFC data standard using XML is named IFCXML. IFCXML is the ".ifcxml" extension of the current IFC data format. It is an implementation of the ISO 10303-28 standard [18]. This standard provides an automatic conversion feature from IFC's EXPRESS language to an XML language. By representing IFC data in XML language, users can perform many operations such as extracting, transferring, using, and merging IFC data between various applications. The IFCXML representation provides for ease of understanding classes in IFC along with sub-classes. This feature simplifies the use of IFC by reducing the complexity of IFC data. Due to the XML feature, the IFCXML file size is larger than the IFC file size (approximately five times).
