This is a great question actually.
“Do I have to start designing with hand sketches and diagrams, or can I just go directly into 3d modeling and computer programs?”
The answer will really vary from person to person. We all work in different ways, and honestly it is nice to switch things up every once and a while. Here a few ways I begin in my design process.
1. The Hand Sketch/Diagram
For me, I love hand sketching. Any time I have an idea, I will sketch it out by hand in my sketchbook. It is pretty effective in getting my thoughts recorded quickly. I like to draw many iterations of the same idea and even try to make pieces of artwork and mixed media to enhance my drawings and promote divergent thinking. I also write a lot. I write key words and terminology into my designs to remind me what things mean, like writing — “Humility?” — next to a space that I want people to feel very humble.
This is a pretty unique trait to hand drawing. It allows you to think differently. The words give meaning to the forms and space. When you are designing in Sketchup, you would have to stop modeling to write those things down, and then the ideas are kept in two different places.
2. 3D Computer Modeling
However, sometimes I have been thinking about my design for a week before I even start to work on it and I want to go directly into production mode. I make a model in SketchUp to get my ideas into 3D form quickly. I am able to get sections, plans, elevations, and perspectives from this. The cool thing about this is that you can print out portions of your 3d model and draw over them to create hybrid drawings. This gives you the best of both worlds.
No matter what you do, or which method you decide to begin with, the basic principals still apply. Determine a reason for doing. Develop a parti or concept as a main driver, and continue to work that idea throughout the entire design process.
An average project has:
A Vehicle - Your process and methods of construction.
Starting point - Your Parti or Concept.
Journey - Your experiments, trial and error, models, drawings, etc.
Pre-conceived Destination - Idea of what you want it to be.
Final Destination - Where the product is when you decide to stop.