Inputs regarding building storage units

[Krishna Vakk]

Hi all, 

I am looking into building a storage units in 1 acre of land that is zoned under commercial use.  Does anyone have any inputs or experience that can provide some inputs on the costing?  I see lot many builders offering ready made structures that can be installed on a concrete pad.  Looking around to see if anyone had gone in the same path and would like to hear some success stories.  

I listed out below areas that need to work on during planning phase.  Any other things that I am missing on?  Thanks in advance. 

1. Zoning and regulations

2. Utilities  (already present)

3. land prepping - Already complete 

4. Engineer plan - Work In Progress 

5. Permits and approvals - Upcoming

6. Work with builders - Research in progress