Assuming there is demand, I would discuss with county and local fire marshals, city planning admin, county engineering, county floodplain, zoning.... how are you getting utilities, are there impact fees associated with them (water / sewer / electricity), assuming it's a state owned road you are on, you will have to get a permit from them as well (Ask your civil engineering company about this), Do you have a survey, does it have topo, what are your setbacks from the road, if it's a large road it may be significant if there is expansion planned, Does it have the required ingress / egress for emergency vehicles (ie. min road widths and entrances), does it have appropriate water supply for the latest fire codes (ask your civil engineering company for references to fire engineers or if they have somebody in staff that can help), where do you need fire hydrants and are sprinklers required, are there any easements currently- will you need to grant any for utilities...
Also, find an civil engineering company who's done similar type work. Once you have a layout or idea, plan a pre-development meeting with the city to see if they're open and willing to support the plan.
Once you have most of those answers, then you can apply costs to them and see if the project makes sense financially. Using the equity of the land to finance the build would be my first question, since you're a real estate agent, you should be able to approximate that value and figure that out.
Feel free to holler at me with any questions, I'm doing something similar with office warehouses currently in TX, but am looking at my next project of doing storages from the ground up.
