Every design starts with an idea. That can be shapes drawn out on trace paper, or a chipboard model, or a conceptual form in a 3D model. This idea becomes the basis for your design and ultimately your building. While you might sketch out several variations on trace paper or your sketch book to give your ideas shape, there comes a point in the design process where you need to begin testing your assumptions. Does the floor plan fit within the building's massing? Does it meet the client's functional requirements? How does it look from other angles and views?