In one embodiment, a design application is provided that utilizes layered analytical modeling in a design and analysis workflow. An analytical model may be described in a model file by a base geometry and a plurality of analysis parameters, including modification geometries that define changes that can be made to the base geometry, loading definitions that define how loads are evaluated, and appurtenances groups and configurations that define the nature and arrangement of appurtenances. A user may select analysis parameters which together with the base geometry define a scenario. A plurality of scenarios may be maintained within the same model file. When a particular scenario is to be visualized and analyzed, the analysis parameters of a scenario are layered on to (i.e. merged with) the base geometry.