Sheds can be a gray area, but from what I can tell, if it has a foundation (and is therefore attached to the land, rather than being movable), it is considered as "Real Property". If that is the case, it is usually depreciated over 39 years and does NOT qualify for Section 179.
If it is movable (not attached to the land), the it is "Personal Property", which is often depreciated over 7 years, and DOES qualify for Section 179 (or better yet, the 100% Bonus Depreciation that is available).
