What are the primary goals of creating a building model? Who are the key stakeholders?
The primary goals of building a model are to create a digital representation of a real-world project to see how it interacts with its space.
Creating building models also allows stakeholders (i.e. project manager, architect & designer, structural engineer, electrical engineer, general contractor, etc.) to visually see how the project at-hand might come to be in the real world, as well as how/where their role might be necessary. Building models basically allow for easier collaboration between stakeholders by having all elements of the design in a digital space.
How much detail should you include in your building model? How do you decide?
Depending on the stage of your design process and the purpose of the design, the level of detail in your model might heavily differ. If you are in the initial phases of a project, a wireframe model with basic design components (walls, windows, doors, floors, etc.) is probably a good base case. From there, you can add more detail to the design as you solidify more aspects of the project.
Many door and window manufacturers provide Revit families for doors and windows that you can specify for your building design.
The advantage to manufacturers that provide families in Revit is that designers and builders can factor that product into their project early on and basically guarantee its use in the project, which generates sales and revenue to the product manufacturers . From the designer’s perspective, having all the specifications and data on a real-world product allows you to develop a more detailed, real-world model that considers everything from aesthetics and size to function and cost.