The cost to build the ADU was $300k labor, materials, fees, architect, inspections, etc.

So be careful before you jump in, make sure any deal pencils out with potentially costly renovations, needing architects, engineers, plumbers, electric, HVAC permits etc.

BUT I did not deny them, I told them all changes will be planned by an architect, permitted by the County building inspector, built by a licensed and insured contractor. 

How an architect missed a support beam and how that plan got passed is a mess.

- Or, do I need to work with an architect to develop a floor plan, then find a contractor who is licensed to do the work, and then submit the plan for a permit through DCRA?

But also is not just about the contractor or builder, is also a matter of the architect company behind the builder - if that's the case. 

You just have to decide how much of your own time you want to sink into this dilemma.Also, I'd be interested to hear if @Prashanth Mahakali or @Samuel Pavlovcik have dealt with similar issues as Chicago Architects.

If you're just remodeling and not changing the structure of the house you don't need an architect.

Should I meet with an architect to go over my plans and then bring those to a contractor rather than having the contractor make those decisions?

The great thing about this house, is it sits on commercial zoned property and after speaking to an Architect, I can fit 4 MAYBE 5 units on it.