Building Information Modeling (BIM)

What is BIM?

In its simplest definition, BIM is a method of designing, building, and operating a system that involves the creation and use of intelligent 3D models. Compared to traditional 2D drawings, these models allow all project partners to have more detailed information about the project, so that much better and predictable building results can be achieved.

How is BIM Different from CAD?

BIM' 3D is much more than CAD; it is more than just a 3D building model. BIM solutions use relationship-based database technology to create "intelligent" models by embedding information and relationships into models.

BIM (BUILDING INFORMATION MODELING) is the naming of a process that can be translated as Building Information System, which we can consider as a new generation project design process, in which all structural and functional information of the structures can be predicted in advance, all disciplines (architectural-static-electromechanical) can join together instantly or afterwards, the cost information is revealed even in the first stage of the project.

BIM(Building Information Modeling) takes place in Turkish language as Building Information System, Building Information Modeling.

BIM is a model-based process that delivers value throughout the building lifecycle.

At the heart of the BIM process, takes place information-rich 3D Models that can be used in
construction and
management processes.

With BIM, we significantly improve the way we plan, design, build and manage our projects.

BIM is the name of an entire system, not a program or product. It can be used effectively in all main processes of the project, for example, it increases the quality and speed of information exchange between employers, designers, consultants, contractors, subcontractors and suppliers, and ensures the emergence of the most suitable product for end users.

The system goes far beyond a visual model with its three-dimensional numerical modeling structure and acts as a multi-functional management and information sharing tool that can be continuously improved, containing all the information about the manufacture of the building. The first thing to do in order to increase efficiency, quality and reduce costs in projects is to increase control over the project by switching to BIM at the design stage. Thanks to the prepared BIM model, temporal planning, cost management, simulation studies and facility management can be managed quickly and accurately.

Building Information System has three basic features:

  • It works with a numeric database that holds all the data describing the structure.
  • Since revisions are made in this database, any change made to any document is reflected in all documents (views, lists, etc.) generated from the database (most of which are generated automatically).
  • All data collected during the design process is stored for later use. This creates a repository of information that can be used not only by the builder of the project, but also by the contractor and owner of the building.

Building Information System enables higher quality designs to be realized in a shorter time and at less cost. Since it enables architects and engineers to work simultaneously on the same building model, it helps prevent errors caused by lack of interdisciplinary coordination. The use of Building Information System is to the advantage not only of the designer but also of the contractor and the customer.

What are the Benefits of BIM?

  • Any photorealistic visualization work can be produced from the BIM model without additional time and budget.
  • Cost estimating can be made directly from 2D CAD data and 3D BIM model.
  • Coordination and superposition studies can be done in 3D environment using BIM model. Thus, possible problems between building elements and systems can be automatically detected, reported and resolved before the work starts on the field. (Clash detection)
  • Work and site planning can be done with 4D Phasing features. Conflicts between jobs can be avoided and efficient construction site flow can be achieved. With BIM, contractors can begin work planning at an early stage of design.
  • A better visual information is obtained in the field thanks to the coordinated BIM model. Components that can be pre-manufactured take their places in the field correctly and on time. Working with the BIM system results in less information and change requests (RFI), and problems to be solved in the field are reduced.
  • Design changes can be made during the pre-design process without a major cost impact, thus speeding up the design process.
  • With the accuracy of the model and the ability to communicate effectively with subcontractors, it reduces the number of information and change requests after construction begins.
  • With material quantities generated automatically from the BIM model, construction cost estimation works are done more quickly and accurately than with the traditional method.
  • It can be used for the management of the structure using the BIM model after the construction is completed. Space occupancy assignment works for spaces can be done easily. (Like rentable areas)

What is BIM?

As stated under the title of Definition in Technical Specification Section A-Common Conditions Article A., “BIM (Building Information Modeling) is the process of creating and using the plan, section, facade, perspective, list and all other necessary information for the document design of a building through 3D parametric, intelligent object-based models by adapting information technologies to the building industry. In addition, BIM is the name given to the system that allows objects to become 4D by entering time data with the help of parameters, and to become 5D by loading cost data to objects.“

The main purposes of the BIM system to be used to achieve different goals are;

  • Carrying out better communication and cooperation among all project team members,
  • Reducing the problems related to design and construction quality, as well as not exceeding the project schedule and scope,
  • Ensuring projects can be delivered reliably, faster, more economically,
  • Gathering the information to be produced throughout the project in a single digital environment.


The use of BIM System is not only limited to three-dimensional modelling, but also aims to use information correctly.

Creating a smart model of the project that includes all disciplines and ensuring coordination in order to increase the quality of implementation Creating the Design
Creation of Design Documents
3D Coordination
Existing State Modeling
Engineering Analyzes
Taking the quantities according to the work items determined by the administration over the created model Creating Quantity Lists
Integration of the activity plan to be made from the prepared models and planning of the progress over the model Phase Planning
Preparing As-Built projects in BIM model and updating the model according to As-Built information Record Modeling
Designing the prepared BIM Model as to be used also in the operation and maintenance phase Creating the Design
Record Modeling

Uses of BIM

The use of BIM is a specific task or procedure that is beneficial when incorporated into the relevant process of a project.

Model detail level / LOD levels, at what level of detail the components to be used in the 3D Information Model should be according to the project stages and which discipline the responsibility of these components belong to, are determined on the basis of the details described for each modeling element in the BIMFORUM LOD Specification 2020.

a) Creation of the Design– It is the process by which the design of the building is converted into an information model and developed using three-dimensional software tools. Definitions related to model structuring are explained in detail in Chapter 13. Model Structuring section and under the title of Minimum Requirements of BIM Model on the Basis of Discipline in Technical Specification Chapter A-Common Conditions Article A.

b) 3D Coordination – It is the process of detecting incompatibilities that may occur between building systems and components through the BIM model, by means of conflict detection software. In the process, first of all, each discipline will provide its own internal coordination. By creating a coordination model from the models created by different disciplines, any conflicts that may arise between the designs will be determined before the construction phase. Definitions related to 3-D Coordination are explained in detail in the appendix “ANNEX-03 Overlap Matrix”.

c) Creation of Design Documents – It is the process in which schematic, concept, preliminary, application and manufacturing drawing sets related to the project are produced over the BIM model. Thanks to the model-based design features of BIM-based software, the process will be managed effectively by automatically reflecting the changes made to all project outputs. Sheets that cannot be produced from the model will be clarified with the approval of the Consultant and Administration.

At the same time, the related images of the project will be created with the help of rendering technique, using the models produced within the scope of the BIM System

In addition to these, after the application projects of the relevant building are approved, Location Information Sheets (RDS) will be prepared from the BIM model, containing the quantitative data of each location and the information about the location. Location Information Sheets (RDS) give a detailed description of all surfaces, fixtures and hardware, mechanical and electrical equipment that will be required for a location in a project or building.

d) Phase Planning – It is the process of planning the stages of construction, maintenance, renovation, reinforcement etc. by adding time parameters to the 3D model.

The 4D integrated model will be created by associating the model with the work program, taking as reference the ideal construction process foreseen for the construction of the project in the main work items. The work program will be made over the main work items as to be the base to the manufacturing work program.

e) Creation of Quantity Lists – It is a process used for quantity calculations throughout the life cycle of the project. Quantity lists to be prepared will be produced based on architectural, structural and electromechanical models for station structures. For each station model structure, separate quantity lists will be created within the model. Detailed information on the creation of the quantity lists is presented in ANNEX-08.

f) Existing State Modeling – It is the process of developing a three-dimensional model of the existing site environment, facilities or a specific part of the field. At this stage, existing state models will be created for the surrounding structures by using the existing bases for the station areas. Apart from the existing state models created for the surrounding structures, 3D models of the current state of the building will also be created, if needed, by choosing the most efficient method according to the desired model, using laser scanning or traditional surveying techniques.

g) Building System Designs (Virtual Mockup) – It is a process used to analyze and design the construction of a complex building system to enhance planning.

h) Site Mobilization – It is the construction process that graphically displays the construction stages of temporary and permanent facilities under construction. It is the process in which the representations of temporary and permanent structures located at the construction site are created over the BIM model. In case of need, it will be possible to examine the construction site requirements in 3D in digital environment.

Sample Kaynarca Station BIM Model Study
Sample Kaynarca Station BIM Model Study
Sample Kaynarca Station BIM Model Study