Advanced approaches and new design technologies allow us to improve productivity and quality, primarily by reducing the likelihood of errors during the design and construction phases. Among these, we include Building Information Modelling, or BIM.
GIC is a long-standing advocate of the BIM approach, being one of the first builders to use it and develop advanced solutions, as well as an active member of the Slovenian SiBIM association.
Building Information Modelling (BIM) is a comprehensive digital process supported by numerous tools, technologies, and contracts, which include creating and managing digital models to describe the physical and functional properties of the built environment. It enables the digital visualization of all architectural, technical, physical, and functional data of the building.
It significantly contributes to improving collaboration among stakeholders during design, optimizing data exchange, and creating a more transparent platform for generating new ideas. BIM is not only used in the design phase or cost estimation, but it also brings numerous benefits during construction, for marketing activities, and even for managing buildings, such as through digital twins.
In our projects, we strive to use the BIM approach primarily because it provides all project participants (from designers, clients, and investors to project partners) access to up-to-date information. The repository is accessible anytime and anywhere, making collaboration easier, reviewing changes simpler, and business operations more efficient. Every project change can be evaluated much faster in terms of both cost and time perspectives.
When we upgrade a three-dimensional BIM model with a timeline, we are talking about a so-called 4D BIM model. If we then add construction costs, we get a 5D BIM model. The next level, 6D BIM, includes the management aspect, i.e., information on warranties, user manuals, maintenance, and other relevant data. Then comes 7D BIM, which considers the sustainability aspect throughout the building’s entire lifecycle. The latest available level is 8D BIM, which focuses on health and safety during project planning and construction.
To better illustrate, we present each stage in the table below:
| Level | Brief Description |
|---|---|
| 2D | Standard design using CAD tools (or manual drafting, without computer tools) |
| 3D BIM | Geometric 3D model of the construction, including all geometric data and the interrelation of individual components |
| 4D BIM | 3D BIM + time; model objects are linked to the construction schedule |
| 5D BIM | 4D BIM + costs; model objects are linked to cost factors |
| 6D BIM | Includes management aspects, such as warranties, user manuals, maintenance, and other relevant data |
| 7D BIM | Considers the sustainability aspect throughout the building's lifecycle |
| 8D BIM | Focuses on health and safety during the design and construction phases |
When talking about the level of completion of BIM models, we also refer to the so-called Level of Development (LOD). This refers to the level that describes how developed (modeled) a component of the model is. The LOD range is between 100 and 500, where lower numbers indicate a lower level of completion.
To better illustrate, we present the individual LOD stages in the table below:
| LOD Level | Brief Description |
|---|---|
| 100 | Conceptual design (The 3D model is developed to present basic information. In this phase, only a conceptual model can be created. Parameters such as area, height, volume, location, and orientation are defined.) |
| 200 | Schematic design (A general model where elements are modeled with approximate quantities, size, shape, location, and orientation.) |
| 300 | Detailed design (The element in the model is graphically represented as a specific system, object, or assembly, in terms of quantity, size, shape, location, and orientation. Non-graphical information can also be attached to the model element.) |
| 350 | Construction documentation (Includes model details and elements that, with graphical and written definitions, represent how construction elements connect with different systems and other construction elements.) |
| 400 | Fabrication and assembly (Model elements are modeled as specific assemblies with complete manufacturing, assembly, and detailing information, in addition to accurate quantities, size, shape, location, and orientation. Non-geometric information can also be attached to model elements.) |
| 500 | As-built – PID (Elements are modeled as-built assemblies for maintenance and operation. In addition to the actual and accurate size, shape, location, quantity, and orientation, non-geometric information is attached to the modeled elements.) |