Don't over-tighten the bolts to the floor.In most parts of the country, ripping out a tub and floor would be considered a bathroom remodel and would require a permit and licensed plumbers.

A permitted second home (2 bed, 1bath) was added in 2015. 

We found out that the flippers had removed a wall (without permits, which they had not disclosed).  

(you can also call the rental permit inspector, they know who the burned out landlords are and will share their names with you).  

When he applied for permit to separate electric panel, the city said it is a single family and gave him violation for the non-conforming unit.

@Kyle DutsonMost people budget 5%-10% for capital expenditures(it can be more or less during a year but thats the average).The age of the house may dictate the number you use - Older homes require more upkeep than newer homesQuality of tenants - Better tenants will take care of home better and require lessdate of capital expenditures done by seller - Permits are usually required when there are big repairs done to a house.

Newcomer here curious about structuring some financing. 

I went to the city of Raleigh permitting dept. to discuss converting this to a rentable unit and was told I am not zoned for a duplex but I could make it into what is very specifically called a "Utility Basement".

He added that inventory is improving as the Jefferson County MLS has seen a 4.8 percent rise in residential building permits.

I use 10%, but I don't have a large enough sample to know if that's right, and most of my units rent for less than $600/mo.Make sure you count up all the taxes carefully as well, including occupancy permits and various other ordinances that exist in the Pittsburgh area.