You can use any type of contract, you can even hand write one on a cocktail napkin. 

Are apartments not being maintained in a sanitary manner? 

But that can get expensive.My lease says, “Tenant shall, at their own expense and at all times, maintain premises in a clean and sanitary manner…”For the next lease, I’ll probably add a separate section on outdoor maintenance.

You haven't provided all factors, but back of the napkin, I'd say what you have sounds competitive and fine.  

I was thinking of explaining how I figure out my deals (napkin method), but I am thinking this is too much for them.

@Varun Parkash - I'd look at the deal and your goals this way (using napkin math and flat rents): You say that you want to purchase this home at $315,000 which would cost say ~$5,000 in closing costs.

Just do it, even if its on a napkin and share.

@Jay Hinrichs I've seen some wholesalers write the deal on a napkin.

Alex HenriksenSome quick napkin math using the 50% rule:Assumptions: Selling price $194KFinancing: Non owner occupied, 25%down, 5%, 30 yearMonthly PI = $781Tenants pay all utilitiesNo big capital expenditures needed.Expenses = Gross rent *.5 = $2320 x .5 = 1160This leaves $1160 each month to pay your mortgage (PI), utilities, and yourself.Cash flow = $1160 - Mortgage = $1160 - 781 = $379/month.

Similarly, just because the 1% rule is not met does not necessarily mean that the purchase is a "bad" buy either.But yeah the concept is pretty much irrelevant to large multifamilies.I think the 1% rule just arose as a back-of-the-napkin rule of thumb for SFRs and small multis.