Grow Room from Scratch - What would you do?

[Biggy]

 
Yep huge difference between how most hobby growers scale and how business scales.  Education is a business after all.  We run a commercial farm but what you are describing pales us by comparison.

Tell me, are you saying you have a high tunnel and a grow room or are they one in the same?  Here there is a huge demand for tobacco starts.  Lots of growers do not like growing from seed.  Typically the people who sell starts by tray (floaters) use high tunnels with heat and some artificial lighting.  Have never heard of any of them having an indoor grow room for starts.  Wondering if maybe there is a reason for that.  Maybe the savings of having some sun light outweighs the cost of heating the things.  Maybe it is just too expensive to build so much indoor grow space.
 

I have both. I mainly start in a grow room framed into my barn. The cost to heat a tunnel is outrageous. A single layer poly tunnel has a r-value of around .5. Meaning it heats up awesome but will be close to the same low temp overnight. On a winter day it may be 80° during the day and -5° overnight in the tunnel. I do start frost tolerant stuff in there. I have some left over 20' rafters that I'm planning on building a 20'x 48' greenhouse using tripple wall polly carbonate pannels. They insulate enough to warent heating. Main factor on heating a tunnel is the weather. I'm in Nebraska so when it gets cold it usually stays cold.

 

[Hafners]

Don't forget a couple IP cameras and a WiFi extender if needed, less trips out to the barn to check on things.

 

[AJ Drew]

Biggy, I tried heating our high tunnel last year.  It was an experiment.  Never again.  I will likely heat it a night or two while extending the season at the start of winter when weather is usually fair but there is a cold night here and there but actually heating it threw the winter is prohibited by cost.
 
But I do still think about the deep winter designs for green houses.  Double layer hard plastic on the South facing slope and thick insulation in every other direction.  I doubt one could grow a crop there during the winter but I am wondering if it might be savings on an in door grow room due to the free light.