Victoria, Australia-based Archiblox designs and makes sustainable, prefabricated modular residential and commercial projects. This simple, straightforward, and modern structure can be used as a studio, office, guest house, or pretty much whatever you desire. Modules can be grouped together for larger spaces and are designed to subtly echo the geometrical arrangement seen in nature.
My advice... Don't do-it-all-yourself. Novice and pro alike can benefit from each other in DIY. You might have the shed location leveled by a landscaper; get a referral to outsource the shed's foundation to a building subcontractor; you can even have the roof's trusses made by a local truss company and the shingles installed by a handyman or roofer.
Cut the treated 6x6s to 12 ft. and set them on the gravel so they’re parallel and the outside edges are 6 ft. apart. On sloped ground, you’ll have to raise the 6×6 on the low side until it’s level with the adjacent 6×6. Do this by stacking treated 2x6s, 4x6s or 6x6s on top of the treated 6×6 to reach the right height. Use a 4-ft. or longer level to make sure the 6x6s are level and level with each other. Finally, square the 6x6s by adjusting the position of one 6×6. Slide the 6×6 back and forth, not sideways, until the diagonal measurements from opposite corners are equal. Build the platform with treated 2x6s, 24 in. on center, and cover it with treated 3/4-in. plywood (Figure B).
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