This activity teaches outline and tonal hatching as a way of describing form. The student starts with the silhouette and builds the building up through shadow rather than detail. Most students want to draw windows and doors first because they look like the building. Hold them off. The shape and the light do almost all the work. Hatching is the curriculum content. Closely spaced parallel lines create dark areas. Spread lines create light. Students will not get this right the first time. That is fine. The second drawing of the same building is always better.