Multi-family on top of new medical office?

[Ryan Schaefer]

Hi everyone. New here, first post! I have some experience with single family rentals but now considering a commercial real estate opportunity and hope to get some expert input.

I'm under contract for some land on which I will build new medical/dental office (my wife will occupy half). We are planning to build some extra leasable space for another professional tenant TBD. 

Here's the opportunity we are considering: Zoning allows for multi-family apartments “second floor and above.” Given current planned size of the first floor, we could add 10-12 units on a second floor. The location seems great for apartments (apartment complex next door is at capacity) and there is growth all around. Does this idea make sense? What is the best method/tools to assess/analyze this opportunity? The total project cost would be at least 2X what we were planning to spend for the first floor medical space (but less on a $/sf basis), so do we continue to try and finance ourselves or is this a deal ripe for a partner?