If you want to build your shed using a pre-hung door then the 10×12-gt gable tall shed plans are for you. the wall height is 7′-7" which allows the 6′-8" tall shed doors to be installed on any wall and still have a 2×6 header supporting the roof.. A 10×12 backyard shed fits in a small yard. if space is at a premium in your backyard consider how small an area is needed for a 10×12 shed. 10×12 is roughly the size of a two compact cars side by side. 120 square feet. get out a tape measure and see for yourself how easy it could fit in your yard..