I am trying to built a raised gazebo to meet my 4' off the ground deck. How do I built the foundation and the gazebo floor? Do you have any plans? Thanks
Build it the same way the deck was done. Set proper footings at the base of each post, then add 4' to the length of the posts to accommodate the elevation.
Pictures and plans are readily available across the internet for basic gazebo structures. If you've got reasonable building skills, then copying what you see won't be a problem. If you're not a competent builder, then leave the work for more experienced hands. Anytime safety is an issue, you don't want to mess around with things you're not comfortable or capable of.
Let me add this:
While plans are readily available on line or other places, building a structure like a Gazebo is a job for the professional, because it involves different trades. Done wrong and it becomes unsafe, so be advised.