Advice on New Construction Multi-Family

[Jourdain Francine]

Hi Everyone,

My wife and I currently own a duplex and are looking to add a larger multi-unit to our portfolio. We would like to research the possibility of doing a new construction fourplex where myself and the company I work for can do all of the HVAC and plumbing. 
I am looking for advice on where to start with this project. Do I go to an architect to work on plans and then get quotes from general contractors before taking the proposal to a bank? 

Thank you for any and all advice!