It really is not hard to install submeters in most cases.

Tankless WH cost has dropped significantly, they tend to last longer and are less prone to leaks but the initial switch might require upgrading the gas line with potential higher installation price tag.

Point of the post : Over time, I have taken the DIY route on a majority of my properties and have learned a ton in terms of trade work.

I have a tenant in Arizona, who moved in a month and a half ago.they keep complaining that the master bedroom is too hot.The whole house is ok but the master bedroom is hot.I offered them a portable ac, they refused took it but did not install.I offered to have a handyman come install it, they said they can do it themselves.I offered the ac guy to come check on the AC and asked them to call the guy, because he likes to schedule with the tenant directly, but they have not called himI asked if they waned me to schedule with the AC guy,- silence.They complain but wont let me schedule for them.I understand that the tenants are just complainers, but I want to cover myself legally.So in case, if they decide to take me to court, I would not be liable.What is the best way to deal with things like that?

You could try and itemize the invoice and DIY the cost seg for the bathroom reno.

I could either 1) install a coin operated set up for the two tenant apartments 2) install another regular set and have two sets in the basement. 

Doing a $50K renovation might take you months, which would mean even more holding expense.And, the same problem you mention also applies in the DIY scenario: What if you take months to make $50K in renovations and then still don't get the offer you need?

@Jackie Liu we see this a lot, where many PMCs and DIY owners only require the last 3 paystubs to gauge income.How can a tenant consistently pay rent, unless they have consistent income?

Better quality product, better installation, and making relationships is invaluable if you plan to scale.

Install should be about half a day plus disposal of the old system.