Starting a design with a sketch risks starting with too much information – and information that is likely not a good fit with the project.
There becomes a risk of working on and strengthening irrelevant parts of the structure at the expense of latent centers that are essential to the project.
Christopher Alexander proposes starting with the fuzziest sense of the whole,
the broadest, most global features of the emerging design. Often these “global” features will extend across the full diameter of the area being considered. At each step, another “ripple” introduces one more feature of the whole.
Alexander’s preferred method for creating these ripples is to stand in the location and imagine the possibilities presented by the physical space, painting the picture with words. Words are a more fluid and flexible way to create imagery than drawing.
Source: The Nature of Order Book II, Page 256
Also on Wild Rye
The risk that comes from moving too quickly to working with images is that you may start using a structure that is outside the scope of the project. You can easily come up with something that looks good on paper but doesn’t really bubble up from the site you are working on. The danger is that Imposed structure hinders thinking.