Autodesk Revit is architectural BIM software for Microsoft Windows, currently developed by Autodesk, which allows the user to design with parametric modeling and drafting elements. BIM is a new Computer Aided Design (CAD) paradigm that allows for intelligent, 3D and parametric object-based design. In this way, Revit provides full bi-directional associativity. A change anywhere is a change everywhere, instantly, with no user interaction to manually update any view. A BIM model contains the buildings full life cycle, from concept to construction to decommissioning. This is made possible by Revit's underlying relational database architecture which its creators call the parametric change engine.
Autodesk purchased the Massachusetts-based Revit Technology Corporation for $133 million US in 2002. The latest released version is Revit Architecture 2008 (April 2007) and AutoCAD Revit Architecture Suite 2008 (which includes AutoCAD 2008 32-bit & 64-bit).
Revit is a single file database that can be shared among multiple users. Plans, sections, elevations and schedules are all interconnected, and if a user makes a change in one view, the other views are automatically updated. Thus, Revit drawings and schedules are always fully coordinated in terms of the building objects shown in drawings.
The base building is drawn using 3D objects to create walls, floors, roofs, structure, windows, doors and other objects as needed. Generally, if a component of the design is going to be seen in more than one view, it will be created using a 3D object. Users can create their own 3D and 2D objects for modeling and drafting purposes.
Small-scale views of building components may be created using a combination of 3D and 2D drafting objects, or by importing drafting work done in another CAD platform via AutoCAD DXF, DWG, or MicroStation DGN.
When a project database is shared, a central file is created which stores the master copy of the project database on a file server on the office's LAN. Each user works on a copy of the central file, stored on the user's workstation. Users then save to the central file to update the central file with their changes, and to receive changes from other users. Revit checks with the central file whenever a user starts working on an object in the database to see if another user is editing the object. This procedure prevents two people from making the same change simultaneously and prevents conflicts.
Multiple disciplines working together on the same project make their own project databases and link in the other consultants' databases for verification. Revit can perform interference checking, which detects if different components of the building are occupying the same physical space.
Revit uses .RVT files for storing BIM models. Parametric objects -- whether 3D building objects (such as windows or doors) or 2D drafting objects -- are called families and are saved in .RFA files, and imported into the RVT database as needed. Families do not require programming skills and there are many sources of pre-drawn RFA libraries.