Good Day Bigger Pockets. 

I am working with a group of investors and we are considering building an 18-Unit apartment complex. I have done the math as it relates to condominiumizing the project and selling it off - BUT in terms of the long-term hold; the numbers do not make sense. 

What number (%) do you all use for management when factoring and calculating the cash-flow-analysis? I am determined to find a way to make this project work and it surely does if all units are sold off independently BUT from a rental stand point I am seeing that cost of construction, plans, permits, city fees, and the dirt itself - this may not work.