You know, my husband and I set up our company about 6 yrs ago because my husband was in sales working with very specific formulas, etc for plastics and raw materials. He's been in the industry 25 yrs. brokering with different companies. At the time we set up the LLC, customers were calling him for advice, etc and then some would send him a "commission" or consulting fee for helping them figure out how to process things, where to get specific material, etc.
He set up the LLC to protect us because we were being paid by these companies and had to make sure everything was on the up and up with the IRS. We never took a salary or anything from it, we just deposited checks whenever they came in. We went through legal counsel and a good tax accountant to make sure everything was done correctly.
My husband is an excellent salesguy but he is very knowledgable on the products and knows where to find them, get the right formula, even make formulas that are currently patented.
Here it is 6 yrs later, and for the last almost 2 yrs he left his job and we are working on this little consulting/brokering company and last year (our first full year) we had sales over 3 Million. I jumped in with Quickbooks and got a tutor to help me and we are living quite nicely, saving very well, and both making a decent salary from this little start up that began with customers asking my husband questions.
So to answer your question...........YES, you are on to something. YES... I would pay a qualified construction person to head my project because I do not know all the ins and outs of construction. I don't know how you would determine fees. What level is his expertise?
As for us, we are in a very niche market, self funded and deal with specific types of companies. We sell plastic by the truckloads so we price accordingly to weight, freight costs, etc.
Get a good business model, good legal and tax counsel... start slowly and you never know what can happen!
Good luck!