Here are the inputs:Purchase Price: $400-450K per propertyDownpayment + Closing Costs: $90-100K per propertyMortgage Payment: $2,000 - $2,200/month assuming $2K/year taxes and $1.5K/year insuranceTotal Monthly Rental Income renting out all the rooms (6 bedrooms x $700 rent per room on avg): $4,200Total Monthly Rental Income renting out all the top rooms (3 x 700) and renting the bottom unit to a family ($1,700): $3,800Total Net Rental Income Before Utilities/Maintenance/Reserves/Capex:  Low: $1,600, High: $2,000Utilities: ~$400 assuming that you pay for everything, internet, heat, electric, gas, water, storm drainageMaintenance/Reserves/Capex: $400 to have enough to cover any items that could need repair, maintenance, etc and accounting for age of house and more wear and tear Total Net Cash Flow Per Month: Low: $800/month High: $1,200/month, Middle: $1,000/monthAlso, I didn't include you adding any extra rental income for for adding utilities to rent/garage spots rent/etc, so these cash flow numbers are very conservative but realistic. 

I think that HELOCs can be very powerful.

Nasty......it baffles me how people can live like that....but I'm not living there so I don't care about the filth....The majority of the damage is done and nothing is going to change the fact that this will need a full rehab at turnover...... no need to eat that $$ now.The only aspect I would stay vigilant on is structural damage.....ANYTHING that is going to rot the floor, walls, ceiling etc or be a fire hazard...... so water leaks and electrical for the most part.....

Cost will depend on a lot of factors: size of the units, how many head units are needed, how well air sealed and insulated they are, window placement and efficiency, difficulty of electrical and running the lines.

See: https://www.cookcountyil.gov/content/just-housing-amendment-human-rights-ordinance- Schedule your free ComEd energy assessment and get free areators, insulation, smart power strips, water saving showheads, etc.

The power of real estate investing is an amazing thing. 

Lesson learned - Don't underestimate the power of a bandit sign!

There's also a small 2nd story 1bed 1 bath apartment above the 3 car garage, so it's already been sub-metered and has easy access to electric and plumbing.

The fire was in the attic, so it caused damage to the roof, HVAC, electrical, etc.A few weeks after the fire, we received an invoice from Fire Recovery USA for about $3,500 on behalf of the fire department for the services rendered to put out the fire.

There was 2004 remodel that updated mechanical, electrical and sprinkler systems.