In construction there's a saying "MEASURE TWICE, CUT ONCE" 

Also, Chicago has very stringent rental rules.

You’ll find you have to go for stupid stuff too, like getting ready to order fridge and you forgot to measure the opening.

When you want to get outside of the box, i.e. cross collateralizing properties, you can do this, but your terms will be more stringent and likely borrowing at higher rates.  

The stringent standards they require prevent a good flipper from using creativity and resourcefulness to bring rehab costs down.

I was followed on foot, followed in the car, and even threatened on a few occasions while measuring buildings.

Regarding aviation, traffic is at around -50%, Boeing is having new problems now related to the 787, and there is the never ending fight about subsidies and state aid alledgedly received by either Boeing or Airbus.Petrol demand han rebounded even less than forecasted due to an increase of new COVID cases.People who used to commute are teleworking and not using their cars, and relocating to less expensive areas, where they can afford larger properties that are also cheaper.The tech industry will do well, only if it is not regulated before, submitted to antitrust measures or to more adverse taxation.

Because the trend towards work-from-home is likely to remain in place even as pandemic-related measures are eased around the country.

You need to measure and calculate sqft. for the job and see if they have enough. 

Land in the path of progress  carefully chosen Timber or AG tracts etc etc.. so there is many ways to slice the real estate orange up.. end of the day though the true measure is IRR not COC .. that is if your ever going to stop being a landlord..