[chrismorse]

Been doing this for a few years. You do not want to build something, then have the building/planning dept on your ass.

Here, in Humble County/Kalifoania, you must have approved plans/permit to build any structure bigger than 120 square feet, or anything with electricity or water. Further, there are set back requirements, building to property line.
If this isn't bad enough, if, you are in a design review zone, youmay have to obtain approval from the "fashion police". Mumble, Mumble

Many counties/cities are more lenient. I will admit to building a few things that "may have" required building permits. I have only had to stop work, or unbuild a project twice in 40 years of construction.

IMHO, it is worth a couple of phone calls to save yourself some potential grief, ($).

Good Luck,
chris