A collection agency, PI, or a company looking to perform due diligence on its customers would have permissible purpose.  

(actually construction of homes)Permit fees What size homes are you planning?

I preach customer service and doing the right thing, that's all great to talk about because it costs you nothing, but here I am needing to put my money where my mouth is.

I have found 2 so far just by passively driving to customers houses.

Don't forget to include the cost for permits, tap fees, impact fees and etc.

I would initially imagine hard money would be out because it's not a basic fix and flip short term loan, this is something that will require permits and plans to be drawn up and approved

Past experience of the customer with the BankEmphasis mine. 

I walked the property and noticed that it was creating a swamp, rather than functioning properly, and pulled all septic permits since 1969.

Also customer service and a liitle bit in sales.

Sit there (or have someone) in the morning to check the customers?