The addition of surface rendering to floor plans provides an opportunity to show the pattern and texture of the building elements and furnishings. In this quick sketched rendered floor plan of a bedroom, it has a stippling pattern representing the texture of the carpet. There are lines and dots for wood grain and horizontal squiggled lines representing the fabric on the bed. Notice around the floor plan, I doodled around drawing different table tops, plants and flooring finishes.
Check out this six minute video where I talk about these texture and patterns.