As a designer proceeds from larger to smaller scale decisions, discoveries are made later in the design process that may raise questions about earlier assumptions. This dialogue between scales is a normal part of the design process and the impacts of all these design parameters working in an integrated fashion ensures building design and performance goals are achieved.
Designers can enter at any parametric to make a decision within a given context. For example, the site may dictate that windows can only be oriented to the west, so the designer can assess the optimal window area and other choices within the context of west-facing windows. In another case, costs or aesthetics may rule out external shading devices, so the designer can determine the best glazing type for the unshaded condition.