I'm not sure if any of them are on BiggerPockets, but I can provide you contacts for loan officers and all types of contractors (GC, electrical, HVAC, plumbing, roofing).

It depends on a lot of factors-location of the bathroom to plumbing, what you are converting into a bathroom, types of finishes and is it worth it (ie is this a 3 bedroom, 2 bath house that you are adding a 3rd bathroom to.

Also what's the plumbing like is CPVC (beige) or galvanized (50 year life). 

Rodent droppings, mold behind the insulation, cement poured down toilet plumbing.

As to what Collin Boyer said, finding a property where the "boring" stuff has been taken care of (plumbing, electrical, no major issues) but where there is a lot of room for aesthetic upgrades is a good idea.

/how would you decide financially that it would make sense to break down walls or add walls or run extra electrical wires or plumbing to get out of it more than what you put in monetarily speaking. 

Updated Electrical Wiring and NEW Electrical Panel, Updated Plumbing and Fixtures, New Ceiling Fan in all rooms, NEW Garage door.

Updated Electrical/Electrical Panel, Plumbing, and Fixtures, New Ceiling Fan in all rooms, NEW Garage door.What made you interested in investing in this type of deal?

Expensive deferred maintenance,  Turnovers from old tenants , furnace died  , city wanting me to replace an entire sidewalk section  , plumbing Leaks ,electrical problems , my insurance canceled me a fridge died ,bed bugs , roaches ,tenants refusing to pay ,a stove died and one of my few paying tenants even died in the unit  !

I have NOT included pricing for appliances.Obviously, there are a number of unknown factors that may affect final pricing but I am confident that my pricing is close.I am factoring in:Removing existing upper deck, staircase and lower deck.Replacing lower deck and stairs within permitted footprint and reducing upper deck.Having concrete foundation cut in order to install new steel door and 2 windows.Removing existing interior deck surface.Digging and removing dirt and debris to create living space as able.Bringing in a separate electrical service with all required upgrades.installing plumbing to allow for a bathroom, laundry and kitchen.I am allowing for sprayfoam to be installed as needed.Framing, boarding, taping and painting as needed.Supply and install flooring and trim.Supply and install new door and 2 windows.Remove all debris including tipping fees.Apply for and arrange for permit and inspections as required.Labour and Material as noted above - $72,000 - $76,000.00Plus HST.The next step, if you wish to proceed, is for a site visit with my electrician and plumber for sure.