The introduction of computational design tools has presented architectural representation with a new sense of aperture to the world it seeks to describe. Where the first generation of digital design tools emulated the dimensions of the drawing board, imitating the orthogonal logics of projective geometry and presenting us with the known territory of section and plan, a new set of descriptions are fundamentally challenging the way that architectural representation is organised. The shared digital platform presents the model as something inherently open. Where the traditions of architectural drawing consolidates the autonomy of the designed (Hvattum, 2004), isolating it within a space of abstracted extension, the digital model is interfaced with the world around it, receiving it in the form of external data flows that describe the endless flux of its environmental, structural or material reality (Kolarevic, 2005; Kajima and Panaggiotis, 2008; Hensel et al., 2010). Rather than presenting the contextual in a diagrammatic manner, passively demarcating the outline of its geometry, these informed models actively calculate the values they embed. As such, the active model comes to lie somewhere between tool and representation. As representations, they declare the intent of the proposal, but as tools they simultaneously calibrate its consequences in respect to the given contexts. The event of computation presents architecture with a new potential for representations that know about their internal as well as external contexts and steer their correlations.