For those who can read them, architectural drawings are a complete description. Most clients, however, cannot picture a space by reading a section or an elevation. 3D visualization closes exactly this gap.
Decisions are seen early
Façade proportions, room heights, material textures and colour harmony are not always clear in two-dimensional drawings. On the model these decisions become tangible and open to discussion. Change requests therefore come up at the design stage rather than during construction.
The cost of a change depends on the stage
Changing a decision at the design stage only requires redrawing. When the same change is requested after the work has been built, it also means undoing what has already been done. Visualization is useful to the extent that it lets decisions be made at the cheap stage.
It creates a common language
When the client, the architect and the construction team look at the same image, the gap in expectations narrows. A detail described in words rarely means the same thing to everyone; a visualized decision leaves no room for interpretation.
It also has limits
Images are produced according to the material and lighting decisions defined in the project. If a different product is chosen during construction, the result changes too. Images should therefore be treated as a reference describing which material will be used, not read as a promise in their own right.
When it comes in
Visualization is most effective right after the plan and massing decisions have been settled. Images produced too early represent a design that will still change; images produced too late can only show decisions that can no longer be changed.