DATA SHARING AND COLLABORATION

Unlike traditional CAD systems, in BIM, building information data are attached to each building object, thus creating comprehensive architectural and structural content libraries plus mechanical, electrical, plumbing, landscape, and other libraries. BIM systems normally allow for various operations on the data created and stored. These include, for example, rich rendering and simulation capabilities, quantity takeoffs, schedules, collaboration, and many more.

Most BIM applications provide ways for seamless sharing of the virtual building data between the project team members. These can be further set up as collaboration environments. For example, internal collaboration between members of one com-pany can be established as follows:

• Create a central database file storing the complete virtual building information.

• Team members work on local copies.

• Team members must have dedicated workspaces.

• Team members send and receive changes regularly from the centralized database file.

External collaboration between various companies participating in a project can be established by sharing the BIM data via different data formats that most BIM systems support. These include, for example,

• IFC (Industry Foundation Classes; http://www.buildingsmart-tech.org/

[publication of the IFC specification])

• DXF/DWG (AutoCAD Drawing Exchange Format/Drawing)

• PDF (Portable Document Format)

• XML (Extensible Markup Language) BIM PLATFORMS

Currently, a number of software platforms support BIM concepts and principles.

These include Autodesk Revit, ArchiCAD, Bentley Architecture, and Tekla Structures.

In this book, Revit is used in most of the examples and exercises. A brief description of these BIM systems is given next.

a^utOdeSk r^evit

The Revit platform for BIM is a design and documentation system that supports the design, drawings, and schedules required for a building project (Autodesk, 2013).

Concepts and Abstract Information

Design Criteria and Schematic Model Data

Fabrication and Operation Data Detailed Design Data

FIGURE 3.4 BIM model data development.

BIM delivers information about project design, scope, quantities, and phases when you need it. It is a software platform with multidimensional capabilities (nD) with tools to plan and track various stages in the building’s life cycle, from concept to construction and later demolition. Thus, Revit provides a practical collaborative environment between different disciplines in the building construction industry.

The platform also offers cloud integration, which helps users create and find the custom objects and components they need to make their BIM models complete.

Revit also supports integrated model exchange management using neutral data forms such as IFC, gbXML (Green Building XML), and DXF/DWG round-trip conver-sion solutions between different applications. It offers extenconver-sion engines that support structural and energy analysis.

a^rchicad

ArchiCAD is a BIM software system offered by GraphiSoft^® Incorporated. ArchiCAD creates a 3D BIM and all the necessary documentation and visualization. Based on pro-found knowledge of the architectural process, ArchiCAD’s BIM simulates the way a real building is constructed. ArchiCAD’s BIM tools cover everything from town planning to intricate details, from functional studies to complex designs (GraphiSoft Inc., 2014).

ArchiCAD enables combining architectural freedom with the BIM with a compre-hensive set of tools that supports the design process. It has direct modeling capabilities in the native BIM environment, with its end-to-end BIM workflow using priority-based connections and intelligent building materials, as well as improved analysis tools. The platform also offers cloud integration that helps users create and find the custom objects and components they need to make their BIM models complete.

ArchiCAD supports integrated model exchange management using neutral data forms such as IFC and DXF/DWG round-trip conversion solutions between differ-ent applications. The platform offers has an energy evaluation engine that supports multiple thermal blocks.

B^entley architecture

Bentley Architecture is a BIM application offered by Bentley Systems Incorporated.

The software provides architects and designers with the tools to explore design options, to make better informed design decisions, and to predict costs and perfor-mance. Design and construction documents are automatically coordinated, eliminat-ing errors and omissions. It supports all phases of the architectural workflow, from conceptual design to construction documentation, and integrates design, visualiza-tion, drawing producvisualiza-tion, and reporting of quantities and costs (Bentley Inc., 2014).

The software has a full range of advanced solids modeling tools, which allow the creation of virtually any feasible form.

The Bentley BIM platform integrates well with other Bentley building engineer-ing, analysis and facilities management applications, such as the Structural Modeler;

Bentley Building Mechanical Systems; Bentley Building Electrical Systems; Bentley Facilities; and more to facilitate a shared multidisciplinary model for team collabo-ration and coordination.

tekla StructureS

Tekla Structures is a software platform for BIM. The software enables users to create and manage 3D structural models in concrete, wood, or steel from concept to fab-rication. The platform supports the automatic process of producing shop drawings along with the creation of computer numerical control (CNC) files for controlling fabrication machines. Tekla Structures is available in different configurations and localized environments to suit different segment- and culture-specific needs.

Tekla offers a free tool known as Tekla BIMsight, which is a software application for BIM model-based construction project collaboration. It can import models from other BIM software applications using the IFC data format and other formats such as DWG and DGN.^* With this free tool, you can perform spatial coordination such as clash detec-tion or conflict checking to avoid design and constructability issues and communicate with others in a construction project by sharing models and review notes. This enables project participants to identify and solve issues in the design phase before construction.

THEORY OF MODELING