Of course not, but required items such as electric, water, gas, and plumbing all need to be in working order.

Getting blinds for house 1 pick up blinds for house 2 /3 while you there.3.

The housing market never ceases to surprise us. December marked a big moment: for the first time since mid-2022, home prices increased year-over-year in all 50 of the largest U.S. metro areas. Yep, every single one.
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Don't forget to change all your faucet aerators and shower heads to low flow it makes a huge difference as well as far as water usage and saving HOT water. 

The unobstructed water views for both front STR units can be challenging to determine additional value compared to other 3-unit properties without views.

Tenant pays all utils except water.  

Water heaters, furnaces, flooring, etc etc, all these things have known life expectancies.

Your PM replaced the water heater because it was leaking.

Then based on @Michael Baum's suggestion, I think I will have my cleaner and/or maintenance person do monthly/quarterly maintenance like using using enzyme based cleaners, grease fighting drain treatments and hot water flushing. 

Or if you are able to connect to public water &  sewer, this would make the investment much easier.