You can cut steel roofing panels with a circular saw and a carbide blade, but it’ll save you a lot of work if you order the panels the right length to start with. Plus, you’ll have a greater color selection if you order the roofing rather than buy off-the-shelf panels. Remember to order in advance, though, since it usually takes several weeks for the roofing to arrive. And make sure the overhangs are the right size so the panels will overhang the fascia slightly.
Build the framework for all four walls. To account for the fact that the front and back walls are different from each other (due to the doorframe in the front) and the side walls must both be sloped (to prevent rain from collecting on the roof), each of these will have to be tackled somewhat differently. It’s easiest to construct the back first, the front second, and the two sides last, as shown in the numbered image below. See How to Frame a Wall for more information before you read the instructions below.[5]

how to build a shed