Older Heating systems, portable heaters, and secondary (wood, coal, pellet) sourcesThose are some of the things that you should pay attention to regarding the age of the systems

So my plate was pretty full, so I could not really deal with having a 3rd tenant move out and have 3 empty houses at the same time so I just renewed the lease with her.I definitely will be increasing the rent in the spring and she probably wont be able to afford it so she probably will have to movebut the question now is: I promised her that I would buy that portable AC unit, but now, since the AC leaked and I had to spend $850 to clean it, am I obligated to buy that portable AC unit?

Another option would be to use portable storage containers.

I noticed tenant has a portable heater.

There was a portable toilet on site for the tenants to use.

The EPA recognized LeadCheck swabs are about $2.50 each, portable (for on-site application), effective (with test confirmation), and fast (results in about 30 seconds.)

My dilemma is that I feel like all my time spent at work is wasted beyond simple intake of money (my health insurance is portable so I could take it with me).  

Also consider lead-times to build, significant cost difference, potential impact if any on the size of your storm pond if needed, your risk tolerance, maybe portables which cost more than units, but quicker and no property tax,  etc.11. 

Would you ever consider replacing old portable units with new portables just to get around city requirements associated with building permits?

Invest in a portable security system.