Is adding a large lean-to roof for a large shed going to exceed the limits for the IBC definition of a shed? The shed (details below) is already at the IBC limits for shed area and height.
The lean-to would be along the long edge of the shed and be approximately 33.5 x 12 feet, no higher than 9.5', with a pitch of 2/12 to 3/12. Posts would support it on the low side.
The shed has a footprint of 28.5 x 14' (399sf). The eave height is 9.5' (IBC definition of shed as I understand it), The shed also has 3' overhangs on all sizes and a dual slope roof (7/12 and 10/3) that results in a total height of about 20'. The projection of the roof is currently 33.5 x 20.
Best Answer
If (as I infer) you are in an area where an "IBC Shed" is not requiring a permit, and larger things are, you either need to separate the new space (so you have two "sheds" that are not actually connected) or you need to pull a permit; unless your area restricts you to one "shed" and then you're simply going to have to pull a permit.
If memory serves, the IBC definition is based on "projected roof area" of the "shed" - so two conjoined maximum-sized "sheds" are no longer a "shed."