We present an interactive system called ArchiDNA for creating 2D and 3D conceptual drawings in architectural design. We developed a novel principle of shape generation called match-and-attach by analyzing drawing styles of a contemporary architect, Peter Eisenman. The process consists of user interaction techniques and a set of rules that decide how one or more shapes attach to another shape. One key ingredient of our process is a unique concept for the interactive semi-automatic shape generation that uses the combination of algorithmic rules of a computer and designers' manual inputs. These techniques enable designers to use CAD software in the early stages of architectural designs to explore conceptual building forms. ArchiDNA dynamically responds to drawing inputs, configures 2D shapes, and converts them to 3D shapes in a similar style. We intend to complement existing CAD software and computational drawing pipelines for intuitive 2D and 3D conceptual drawing creation.