How high should my posts/attachment points be?

There is no hard rule on this and depends entirely on what is practical for your space. In most cases your average person must be able to walk under the sail, so we suggest a min in of 6 feet for your average person. If you can position one of your corners somewhere where no one will walk and you want water run-off to be channelled there, you can go as low as you want, including putting your attachment point at ground level.