Very cool. I love these DIY office setups.
The author mentioned organizing material transport by figuring out what would fit in his car. I would highly recommend just renting a flatbed truck from home depot to transport your materials home if they don't fit in your car. Its usually something like $20 to rent for an hour.
Also I wonder if the author has any plans to heat/cool the space. Seems like they might live in a temperate area. I'd would probably just install one of those DIY mini-split units to heat/cool the office if necessary.