What are the primary goals of creating a building model? Who are the key stakeholders?
The key stakeholders in building a model are the people who will use it the most, the people who will build it (in this case, the same people), and the people who will pay for it. It is important to keep in mind how it will function with day-to-day use, not just how it looks as a model and floor plan, and also to keep it reasonable to build and pay for.
How much detail should you include in your building model? How do you decide?
For the initial design, very little detail is needed, as you will presumable continue to edit and improve your design as time goes on. Of course, because of this, you can continue to add details with each new part of the design you feel confident with. The key stages of design are the initial walls/outline, the rooms/doors, and finalizing the indoor components and finer details. It’s generally a bad idea to include too much detail in the sooner stages because then you have to move things around if you want to edit rooms or outlines.
Many door and window manufacturers provide Revit families for doors and windows that you can specify for your building design.
If architects designing in Revit create a building using their specific doors or windows (with potentially unique dimensions or building specifications), then once their plans are finalized, engineers and builders are incentivized (or even forced) to purchase the doors and windows used in the plan. By using the provided doors and windows, architects can be sure that there are real-life windows and doors that fit the designs used in their mock-up, especially ones that match the look of their vision.