BIM Definition: A computerized model of the proposed building in virtual 3D space, using intelligent components, inserted at precise orientations, into precise locations in this space.
-Crotty, R. 2012. The Impact of Building Information Modelling: Transforming Construction. Edited by Crotty Ray: Milton Park, Abingdon, Oxon; New York: SPON Press.
Most people that are even familiar with BIM believe that BIM is just a CAD 3D model. Yes, BIM models are done in 3D, but that is only a small piece of what BIM actual is. In construction BIM is used for project programming, project design, preconstruction, construction, and post construction.
BIM Project Programming: Some organizations have been integrating BIM with GIS (Geographical Information Systems).
Benefits of GIS-BIM:
– Help determine potential locations for an owner’s requirements.
– Lower the expenses associated with demolition and utility demands.
BIM Project Design: Allows for Schematic Design, Detailed design, and Construction Detailing
Schematic Design: The owner and designer are able to examine many different design options.
Detailed Design: 3D models are designed and give the owner and contractors to view interior and exterior models. A computerized walk-through of the building is able to be performed.
Construction Detailing: A 4D model is created. (4D model- is a scheduling model of the project. For example, March 1st can be entered into the 4D model and the building will be in 3D and show what the building will look like during construction on March 1st.) Shop drawings and fabrication drawings can be created in this phase of the design process.
BIM Preconstruction Phase: Estimating, Site Coordination, and Constructability
Estimating: Based on data of 32 major projects, the Stanford University’s Center for Intergraded Facilities Engineering (CIFE) reported that the accuracy of BIM-based estimates was within 3% with up to 80%-time reduction in generating these estimates (CRC Construction Innovation, 2007)
Site Coordination: Trades and different contractors are able to coordinate the installation of items on the project.
Constructability: Using BIM models the contractors are able to plan sequence of operation at the jobsite.
BIM Construction Phase: The contractors and trades are able to monitor progress, have a helping tool for coordination’s meetings, and RFIs and change orders are able to be updated into the BIM model.
BIM Post Construction Phase: Maintenance work order management, Emergency service request management, Space planning and management, Inventory management and inspections, Move management, and Real estate profile management.
Reasons why BIM is used in the Mechanical Industry
Many mechanical systems are very complexed and take up large areas and space of buildings. Today with everything being high pace, prefabrication has become a necessity for construction. Pipes are expensive to rework because conflicts were not noticed in a 2D drawing. BIM is capable of performing clash detections to make sure trades items are not clashing with each other. As-built documents are easily produced in BIM models. Information can be entered into the model to show the exact location of where a pipe was installed. Estimates can be performed a lot easier because the model gives less unknown issues. Schedules can be better coordinated with other trades because the 3D model helps show what is actually in a location.