Plan to Grow 16 Indoor plants... How much space and How Many Lights/Type and Watts?

[demoreal]

I would do 16 plants on a 3x3 tray.
Thats my style.
It could vary depending on what kind of strain it is and what growing style.
I would build a grow room that fits a 3x3 tray.

Then again I know people that grow two plants on a 3x3 tray.