White space can be used as a design element to give suggestions or to provide a little breathing space to a sketch. Sometimes what you don't draw can be as important as what you draw.
The sketch above is of the Asian Civilisation Museum. I've purposely left out the left side of the museum because they are just repeating windows.
Here's a piece I sketch at Amoy Street. I was sketching with some friends and they had moved on. So I just drew an outline for the buildings I didn't have time to finish, and added the text later on at home.
A Bernand Fuchs sketch
If you have any favourite examples of other artists using white space in sketches, share them in the comment section below.