... require 'building out' the new space. There are 220 volt outlets already installed in many areas. Lots of them. One contractor seemed excited about "all the power" already there. Is there an advantage to utilizing the 220 volt power in the space? If so, what is the best way? Can we plug all the normal things into the outlets? Would the 220 volt power help keep our light dimmer (6 dimmers running 5 lights each) switchplate in the studio from getting hot? Any helpful ideas and/or suggestions would be most appreciated - Electrical Layman.

No you can only plug in 220 volt items into a 220 volt outlt, I have no idea what yoga school has that would be 220?
A window air unit, perhaps some commercial exercise equipment ?

But you will not be running lights or fans and the such off it.

If your switch to your lights are getting hot, it is too many amps for the wiring, and/or a breaker larger than the wiring and a seroius fire issue.

Dimmers get hot normally. When ganged together, the load on each dimmer is to be derated to compensate for the heat that will be created. Some or all of the 240 volt outlets can be converted to 120 volt receptacles that will be needed.

Your electrician should be able to handle both issues.