RC,
There is one very important fundamental thing that I learned about building structures. If you are going to get 4-foot-itis, the time to do so is BEFORE you commit to the dimensions.
When you are building a house, cabin, or garage, and the design is a basic rectangle, stretching the dimensions is the cheapest and easiest way to gain square footage. The key to this thought process is the basic rectangle form. What do I mean? I will give you an example.
Let's consider a simple gable home design. Say, oh maybe, 18' x 24' long. The gables are at each end of the 24' length. As this structure is being built, the vast majority of time and detail is spent at the gable ends. Everything in between the gables is simple, repetitive work that moves quickly and creates square footage just as quickly. The devil is in the details, and he lives at each end of the house. It would stand to reason, then, to add square footage in between the gables, you would be adding to the simplest and quickest construction areas. In the end, you spend the exact same amount of time and detail on the gables...only diff is that they are a little further apart from each other.
My gambrel roof gar/apt project is exactly the same situation. In my case, not only the gables, but the ends of the shed dormers. All the time and detail was spent in these "end" details. All the walls and roofs in between flew by in no time. That 28 x 44' project was almost dialed in at 40' long....then I got 4-foot-itus. No regrets.
