Shed plan information like floor framing plans, wall framing plans and roof framing plans are necessary to insure that you end up with the shed you thought you purchased the plans to.. Once you have done this, you are ready to create the second story where the manually drawn shed dormer will be created. to create the second floor select build> floor> build new floor, choose to derive new 2nd floor plan from the 1st floor plan and click ok to display the floor 2 defaults dialog.. This approximately 440 square foot plan for a home addition provides two large bedrooms and a bath in a new dormered rear. this kind of shed room dormer is adaptable to one and one-and-a-half story homes, but it is most suited to homes that already have a stand up attic under a steeply pitched roof..