@Jameson HootonI think I understand where Joe is coming from but I do think the question you asked is an important one.If you are shopping for an IT business, for instance, a good brokerage will make sure that a seller estimates not just the income and balance sheet associated with that business, but also the time needed to maintain the business.Maintaining and growing are two different things - however the way I've 'thought' about your question is the following:When taking on a project, I like to think about the equity (wealth) position of our family's overall balance sheet, and how long it takes me to complete the project, start to finish. 

There's a wall on each side of where two modules meet, for instance.

like @Jairo Ortega said see if your zoned properly first, then if everything check out then see if your quadplex is desirable in your area, for instance i understand the need for more cashflow but maybe your neighborhood is more family supportive so 3 beds make more sense for people moving there also take into consideration 1b units have higher turnover etc. after all that you still are good to goif no structural is needed just a wall to split living space and a new kitchen youre looking at 15k each unit so 30k plus new meters @ 3k each 

Purchase price: $75,000 This house sits on about 16 acres and was once owned by the famous Pat Garrett, the sheriff who shot Billy the Kid.

Mainly what it actually means to refinance a loan, for instance I just learned you can only take out up to 70-80% of the ARV.

In the case of rentals, you'll have to check to see if the building is full of violations by visiting the "buildings dept." here in NYC for instance.

For instance, I'm looking at a 6-unit that is running off a single, electrical, gas, water, hot water source. 

For instance, do your savings provide you with $50,000 capital to invest, $500,000 capital to invest, or $5 million to invest?

you can divide by sqft.. for instance if its a 2000 sqft complex and you charge 200$/mnth for water then that is .10c/sqft so if Unit 1 is 800sqft then there water bill is 80$ etc.

Cities like Indianapolis for instance can vary block to block and even street to street.