The paper reports on CKB (Construction Kit Builder) -a prototype CAD program that designers can program with
positioning and assembly rules for layout of building elements. The program's premise is that designing can be
understood as a process of making and following rules for the selection, position, and dimension of built and space elements. CKB operates at two distinct levels of design: the technical system designer, who makes the rules, and the end designer, who lays out the material and space elements to make a design. CKB supports two kinds of rules with constraint based programming techniques: grid and zone based position rules, and assembly rules that position elements with respect to one another. The paper discusses the rational for CKB and describes its implementation.

Construction Kit Builder, Smart Objects, CoDraw