When you use the Revit rendering tool, one of the most effective ways to reduce the amount of time required to render an image is to reduce the number of model elements that the rendering engine must consider. Use one or more of the following strategies.
For example, if a rendered image will not show furniture that exists on the far side of an interior wall, hide the furniture in the view before rendering. By doing so, you reduce the number of elements that the rendering engine must consider during the rendering process. See About hiding elements in a view.
Change the view’s detail level to coarse or medium. By reducing the amount of detail in the 3D view, you reduce the number of objects to render, and thus reduce render time. See Specifying the Detail Level for a View.
Render only the part of the 3D view that you need to show in the image, omitting areas that are not required. You can do this using a section box, a crop region, the camera clipping plane, or a render region. See Define the View Area to Render.