Shape

365 Seeing Won’t Do—Design Needs Words
requirements—even architectural programs—that set goals to guide and control the
design process. For example, I can give a number N of rooms and then search through
villa plans to find those with exactly N rooms. My description rules can be applied by
themselves to define N, and this in turn tells me how I should try rules to produce
plans. Suppose that N ¼ 8 in a three-by-three villa plan. Then my description rule is
N fi N 1
and I have to apply the rule
as I did for the Villa Angarano. But if N ¼ 5, there are six options. In particular, if the
number five is obtained in a three-step series—maybe this one
from step 8 9 10 11
N 9 7 6 5
—then the plan
is the only one I can produce. Two other three-step series are also possible
from step 8 9 10 11
N 9 8 6 5
N 9 8 7 5
The first results in the same plan—remember that rules apply nondeterministically—
while the second is simply a dead end. No plan can be produced according to the
descriptions in the series—there’s no way to go from step 10 with seven rooms to step
11 with five rooms, that is to say, from the plan