Life's circumstances are too unique and fluid to set arbitrary triggers.One thing  you may want to also put into the hopper for consideration is a partial exchange.  

I know that renting with dogs is rough, and I am willing to pay significantly more than many for a smaller apartment, simply because they a) allow dogs (multiples, and large), and b) have hardwoods that will hold up to the inescapable "messes" that come with having dogs (yeah, bodily fluids, but also mud, snowy paws, and lots of fluff....)

The great thing about house hacking and REI in general is that it's fluid (mostly) and if something changes and something brings you back to Chicago you can keep your Colorado rental, and pick up a new one when you move to Chicago.

@Martin SaenzI agree with a lot of what you wrote and would like to add That I think the process is a little more fluid as with notes most people don’t know what they don’t know.

Transmission shop that was a gas station across the street, makes me wonder about old gas tanks.

Being cash fluid also allows you to pull the trigger on other down payments if an opportunity presents itself.

The building is a high rise and has had problems with noise transmission from prior installs so no one is allowed to put in laminate or similar now - it must be carpet.There is a lighter shade that I quite like, but the advice I had read was dark shades are best in rentals.All advice welcome.

But commercial is a fairly fluid term.  

But do you have the stomach, can you control the risk, developing will take about 3 years from seeking land to full occupancy thus lost cash flow, financing is tougher and fluid, Interest rates will be different in 3 years, etc.

Working in the energy sector I know being near transmission is very important and with California's goals of 33% renewables it could be a lucrative business to own land near large transmission lines where you have access to water and roads to build solar or wind.