Complete environmental design tool which couples an intuitive 3D modelling interface with extensive solar, thermal, lighting, acoustic and cost analysis functions. ECOTECT is one of the few tools in which performance analysis is simple, accurate and most importantly, visually responsive. ECOTECT is driven by the concept that environmental design principles are most effectively addressed during the conceptual stages of design. The software responds to this by providing essential visual and analytical feedback from even the simplest sketch model, progressively guiding the design process as more detailed information becomes available. The model is completely scalable, handling simple shading models to full-scale cityscapes. Its extensive export facilities also make final design validation much simpler by interfacing with Radiance, EnergyPlus and many other focused analysis tools.