Utilizing the example above, our gross revenue in year 3 is $100,000 because the tenant's lease dictates that their rent is $100,000. 

Do you have each student sign a lease per room?

Account Closed : We are renting out the top 3 bedroom flat of the duplex on an annual lease and living in the main floor flat. 

I could update the lease to state tenants are responsible for any fines from the city but in a multi-family unit determining who is at fault will not be easy. 

. $500 summer lease-this is around average rent for off campus house with Utilites includedExpensestaxs- $1,700insurance- $2050gas- $1,900Electric- $1,200Water/Sewer- $2,000Yearly maintance- $1,000total= $9,850NOI based on Semester Rents Without Summer leases and late fees $26,000($16,150)Purchasing Home with Primary Home Equity. 

Should they all still be on the lease?

I don't want to say go ahead because not offering the rent rolls or the lease is pretty big for me, just offering some perspective on the C of O situation. 

All 3 units are currently rented on 12 month leases, only 1 of which will expire in 2018.

If the numbers make sense today, that should dictate your decision.If you are doing a buy and hold strategy, even if the market tanks usually rents don't drop too low and you'll have a 1 year lease anyway with the tenant to help preserve some of your rent income.

You also want to find out the percentage of owner occupied units vs those leased, and the number of sponsor held units if any.