This paper describes a novel approach to explore a multidimensional design space and guide multi-actor decision making in the design of sustainable buildings. The aim is to provide proactive and holistic guidance of the design team. We propose to perform exhaustive Monte Carlo simulations in an iterative design approach that consists of two steps: 1) preparation by the modeler, and 2) a multi-collaborator meeting. In the preparation phase, the simulation modeler performs Morris sensitivity analysis to fixate insignificant model inputs and to identify non-linearity and interaction effects. Next, a representation of the global design space is obtained from thousands of simulations using low-discrepancy sequences (LP tau) for sampling. From these simulations, the modeler constructs fast metamodels and performs quantitative sensitivity analysis. During the meeting, the design team explores the global design space by filtering the thousands of simulations. Variable filter criteria are easily applied using an interactive parallel coordinate plot which provide immediate feedback on requirements and design choices. Sensitivity measures and metamodels show the combined effects of changing a single input and how to remedy unwanted output changes. The proposed methodology has been developed and tested through real building cases using a normative model to assess energy demand, thermal comfort, and daylight. (C) 2017 Elsevier B.V. All rights reserved.