Maybe consider installing Mini-Splits in each unit, each wired to their own panel.....very efficient (depending on kwh prices).

Install Mini-Split systems in each unit.

This to me is one of the problems of the accredited investor definition, 40 years ago $200k you were wealthy, today lifeguards in california are accredited and people take their $250k in savings and dump it into one syndication and losing it all  -and most cases its not a scam its investing as Jay mentioned as someone who invested in $100k rentals into large MF which is like trying to back up a mini cooper into a parking space to a 50' tractor trailer. 

I would look at a mini split unit.

@Min Zhang hi Min, i think finding all the property managers and contractors seems intimidating

One unit that I’m living in is already renovated as a mini split new floors all that.Hi, I’m looking for ways to increase the value of my four family without displacing tenants to do renovations.

Hire a mini excavator to lay the water pipe your self.  

My plan would be to install all new flooring, paint, install mini splits, and laundry hookups for each individual units and swap out the community water heater with a tankless system or maybe individual water heaters.

A mini putting green, cornhole, string lights, or even just a cute hangout area with shade can really boost guest experience without the extra install and maintenance a sauna would bring.Also, small things like a beach wagon, chairs, umbrella, or a cooler can go a long way.

Think of it like running a mini-dorm or co-living setup, higher cash flow, higher touch.Here’s what you should expect:1.