I've planned a new observatory, a Sirius 3.5M dome with an ME inside carrying 3 telescopes.
However, as the dome arrived on time and the concrete base wasn't ready, it sat in its crate, very well packed for a month. So well packed and the sections nested so well that I couldn't see the goods well enough to check details.
Your instructions for the height of the pier said; the height of the walls less the height of the OTA at my latitude. The walls are 5' and the OTA height is18" so I had a 10" dia pier made 42" tall and added 6" for surity.
Then we opened the crate and set the dome up on the base and find that though the walls are 5' high, the bottom of the shutter opening is a further 14" higher. My 6" extra wasn't nearly enough.
It means I'll have to let a 14" section of steel tube into the middle of the pier to regain the lost height.
A lesson for me to be sure, reinforcing the old addage; measure twice and cut once, but may I suggest that you add some clarification to your guide lines, in case someone else takes you as literally as I did.
Regards Brian