Silhouettes are not very common in the architectural sketches. Generally, because the architects put all of the emphasis on the objects rather than decorating the sketch with people. However, there are interior designer and specific design that need to be in combination with people. For example, the interior design of offices, restaurants, furniture or else. Thus, the tutorial in this video shows you how to incorporate the people in the sketches, but still keep the design into the main focus.
Silhouettes in Architectural Sketches
See the amazing tutorial below and learn how to draw many types of people in different positions.