My consideration for this is to do this as a subject to with installing a tenant buyer in there.

Since the sink is integral to a salon and this overflow not something normally needed, I would say you as tenant would be responsible to install (and pay for).  

I have alot of experience in doing "retro fit" installs in houses being rehabbed and or flipped.

I suspect you will also have to get hard-wired and interconnected smoke detectors installed since you are in the process of re-wiring.

You could buy notes as well, but this requires access to substantial cash.The reason I say “control” is because it is possible to build CF without actually taking title to property; sandwich techniques such as option/lease option/installment purchase and then turn around and do the same or simply rent.

Lowes is a bit more expensive but the $75 whole house install is just tough to beat.Not to mention the fact that when I first started and tried to get installers lined up, they were never very reliable for me.

I have a carpet man store that offers commercial grade carpet and pad for $1.25 per square.....installed.

We installed the parts and were paid in most cases before we left the home.

Recently on 2 SFH rentals we had to seal our WBFP's then have them re-inspect it to avoid losing our Insurance.On a higher end SFH I took out the old WBFP & installed a Gas insert with blower & they love it.We did have an issue in an old rental home years ago where the fire was so hot the support joists under the hearth actually started to smolder.

I measured and was just short, but found out the rate would be reduced from over $2k to $250.I ended up closing on the property and had the $2k sent in for the premium as part of escrow as the bank required, but had another vent installed a few days after close.