My presumption is you are looking at a unit inside Kimball or BB Runyon (there are others but I know these have rough in units). This can be done but is a process and there are many factors to consider. Do you plan to supply the materials yourself, or want to stay in trend with what the building has? Are you a GC? Funding will be affected by the route you choose. I am actually in the middle of this exact scenario as we speak.
I work with Urban Omaha/Omaha Real Estate Group; we represent a large percentage of the transactions downtown and have in depth knowledge of the buildings. Email or call me with other questions and answers (a call would be much more efficient as there is much to discuss).