As with any building, a firm, level and square base is needed. Without it your garden shed will become unstable and will deteriorate rapidly. A properly prepared pad will help to prevent rot and make maintenance a lot easier. There are some considerations you need to think about before you decide where to place the pad. Check on restriction, site conditions to include landscape, low spots that may flood, accessibility and aesthetics of the shed in your yard.
Mark the four corners of the garden shed with wood stakes to give you an idea of where the shed will sit.
Do some research to find out if there are easements, setbacks, neighbourhood restrictions or building permits that you need to deal with.
Contact the utilities and have your property flagged.
If the shed can be where you staked it out proceed to step 5. If not, relocate in an area that will work with property restrictions.
Remove the sod where the garden shed will sit and an additional 12 inches around the perimeter.
Level the pad with a carpenters level and a 2x4 piece of straight lumber.
Install four shed anchors at the four corners at a slight angle away from the shed.
Add 4 inches of gravel over landscape fabric and level.
Check that the site is not in a low spot that stays soggy. The city or town hall is a good place to start to check on restrictions. Contact the cable, natural gas, electric, and water companies. Also check for sprinkler systems or any landscape lighting. Always wear the proper safety equipment when building or landscaping
Make sure there are no restrictions, otherwise you maybe required to tear it down.