First, they are all drawings of geometric shapes: buildings comprised of straight lines, flat parallel surfaces and right angles.
Second, despite the fact that each drawing started out as essentially a mechanical drawing, at some key point the artist turned away from the unforgiving laws of perspective, the T square and the triangle, and instead injected the drawing full of character and personality.
The brilliant Bernie Fuchs sketched these buildings in the slums of San Juan. Fuchs seems to have a god-given talent for finding the design in any situation, including this row of squat, ramshackle buildings.
When Rodin drew the massive facade of this building, the shape that interested him the most was not the stone blocks or the massive pillars, but rather the shadow in the doorway. The shadow is insubstantial compared to the weight of the stone structure around it, but it dominates this picture, and enabled Rodin to make a nice, modernistic design.
Cartoonist Jeff MacNelly was a superb draftsman whose understanding of weight, volume and perspective gave his cartoons of buildings and heavy industrial vehicles great credibility. In this typically marvelous example, the geometric shapes of the house have as much humanity as a human face.
In each of these drawings, the artist had to begin with a foundation of traditional knowledge and technical drawing skills, even if those rules were quickly abandoned. Each drawings turned out wonderfully opinionated-- the artists were able to imbue a stone block with character, and portray a brick with personality. But their opinions are far more believable because the artist had mastered how to draw the mechanically correct version.