I don't know how to investigate this further.Another reason I am inquiring is because we are debating on installing a coin operated washer and dryer on the premise because our water bill for 3 units is over $300 a month and I am guessing a lot of that is because two of the units have washers and dryers.So if they can still do their laundry while giving us a little extra money or at least evening the price out that would be the ultimate solution, but if the shared water would still be an issue then this would obviously become a problem if the tenants electric bills start to go up.

New water heater installed in B unit as well, just a few months ago.

I know of a guy that simply gets a VOIP line to run the intercom and the "Phone calls" go out that way to the tenants' phones.I think he said the company that installed the security cameras also did this install.

Essentially it's such low ampage that anything would do, but I'd like it to be compliant.I've been reading the code, and I'm making one alteration to make the installation an extra half inch from the roof deck (they were going to be 1.5" from deck, now 2"), but I can't find the exact codes for the wiring type.I have found some CL rated speaker wire in 18gauge, rated for 150v.

you will need to install a non combustable surface at floor level in that area if you leave the fireplace in.

Could be a number of things like improper install, wood shrinkage, framing deflection. 

Plus we decide case by case what we feel like doing.What we do ourselves (in general) - We paint both interior and exterior, hang and tape drywall (but on the last big drywall job we hired a couple of guys to hang the ceiling pieces), we fabricate and install trim, hang interior doors, install some flooring.

For color variation I looked at the lot number on the boxes and pulled from six different lots when I installed.

@Josh Cohen - Bigger Pockets has two great books that can be found here - The Book on Estimating Rehab Costs is a fantastic source of numbers, while The Book on Flipping Houses is a fantastic source of strategy.I believe that you can get them in PDF form or hard copy from either BP or Amazon.To give you an idea of what the first book has - an example page is for flooring, where it will go over all of your options (laminate, hard wood, tile, etc) with cost per square foot, installation cost, comparisons for how long each option will last before needing to be replaced, etc.

I will stay away from the ultra cheapo stuff but want to keep material costs below $2/sqft and will install myself.