The articulation of the Science of Design by Herbert Simon and the paradigmatic relevance of Artificial Intelligence in that context are closely intertwined topics: Simon elaborates the ‘Sciences of the Artificial’ in the context of the design of artefacts. Situated in this AI-centric view of design, we characterize “spatial computing for design” as a specialisation concerned with the development of the general representational and computational apparatus necessary for solving modelling and reasoning problems in spatial design. Several representation and reasoning problems are dis-cussed in the backdrop of relevant examples involving the formal modelling of structural form with respect to a desired/anticipated artefactual function. The discussion, although applicable to any spatial design activity, is grounded in the domain of assistive decision-support in the context of a conventional computer-aided architecture design workflow.