8. 3-D Models, Formats and Model Structures
The BIM(s) shall consist of objects and elements that represent the actual dimensions of the building elements and the building equipment that will be installed on the project. Before modeling begins, the BIM Manager will work with the Design Team to develop the model and model view extraction structure for all the construction document files to assure coordination between disciplines. This structure shall be provided to VA so that the models can be reconstructed at a later date. BIM coordination requires the following model structure and features:
- The BIM Manager shall establish the floor elevation protocol so that the Technical Discipline/Trade BIMs will be modeled at the correct elevation.
- Clearance Reservations: All models shall include separate 3D representations of required clearances for all mechanical equipment for repair, maintenance, and replacement, light fixture access, overhead cable tray access, etc. These clearance/access models should be in a separate layer(s) for each trade clearly labeled as such.
- The granularity of elements in the model shall correspond with the proposed sequence of the installation at the site (e.g. not one wall element for the entire floor).
- All 3D model files submitted for clash detection shall be "clean;" all extraneous 2D references and/or 3d elements must be stripped from the models.
- When emailing notification of file uploads or for any other email correspondence pertaining to the project, all email subject line headings must be prefaced with the acronym for the Project Name.
8.2 Subcontractor Coordination
Prior to installation, the Contractor shall hold trade coordination meetings with subcontractors. The coordinated model will be used to review and optimize scheduling and field installation. Subcontractors will be expected to have individuals attend who can actively engage in the subcontractor coordination process and make schedule commitments.
8.3 Digital Fabrication
The collaborative process will ensure that the deep knowledge and associated efficiencies of the fabricator are embedded into the Construction Model(s). The following construction trades (at a minimum) shall provide 3D fabrication models with parametric model objects:
- Structural Steel
- Mechanical System Duct
- MEP subcontractors (incorporate vendor models if available)
- Curtain Wall
- Building Envelope Systems (rain screens, pre-cast panels, glazing systems)
- Casework and furniture systems
- Any additional fabrication models generated by subcontractor.