Shed and Gazebo Foundations
When preparing to build a shed or gazebo foundation, several factors are important. The first is understanding that FLAT isn't necessarily LEVEL. An ideal garden building site is both FLAT and LEVEL. Flat means that the ground doesn't have any significant bumps or high and low spots. Level means that there is no grade change between all dimensions of the building foundation.
The easiest way to ensure that the site of your new shed or gazebo is flat and level is by using an 8-12 foot 2x4 or other board. Holding the board on edge, screed the dirt back and forth to ensure that it is FLAT. Then, using the same board, place a carpenter's level on the top of the board and check the bubble's position in multiple directions to make sure the site is LEVEL.
Once your site is FLAT and LEVEL you are ready to build the floor of your kit garden building. If your site is composed of dirt, you may place 12 inch square concrete stepping stones at 2-3 feet of distance apart to support the rim joists of the floor. You may also lay a bed of crushed rock or gravel.
There is no need to secure your shed or gazebo to the foundation unless your site has very extreme or specific conditions.