'Tripolar model' here refers to the model, often also called '3 P model: Profit/Planet/People' or '3 E model: Economics/Environment/Equity', which is very widely used as the reference model for any project in sustainability, including sustainable design. The purpose of the paper is to present a critique of this tripolar model as it is structured and used. The research is based on the empirical evidence that too many projects based on this model have run into serious difficulties or have failed. The critique of the model is carried out in two steps. The first concludes that there is a lack of complex intelligence in handling the systemic logic of the model. The second shows that the anthropological foundations of the model are fallacious. A corrected version of the model follows, with a renaming of the three poles: comprehensive economics, social equity and human creativity. The new model is then discussed with regard to the so-called 'social threefolding' principles of philosopher Rudolf Steiner (1866-1925), which refer to the three ideals of the French revolution. In this perspective, Fraternity should be associated with the economic pole, Equality with the social, and Liberty with the cultural/creative. This model is currently used throughout the world as a basis for various initiatives, on scales ranging from local enterprise to national political economy. The paper concludes with the proposal that the model seems fruitful for the conduct of sustainable design projects.