My prediction was flat for the year, but I think we may see 3-5%. 

It's a flat amount charged per day that rent is late. 

Think like a guest: you don't want your socks to turn black while walking through the house, have a crappy mattress with flat pillows, rough sheets, not enough paper towels or toilet paper, bad wifi, etc.  

Several methods come to mind for the ADU.   1) a regular or periodically adjusted flat fee (based on an estimated usage); 2) factored into the rent (essentially the same as a flat fee); 3) percentage proportionally based on sqft. 

Is there another cheaper flat material i can use instead of fiberglass inserts?

No monthly fees, just a flat rate per year, per transaction.

@Julie Marquez In the past I've hired a builder on a flat rate to build whatever it was I wanted, and that's worked really well.

I would be tempted to try behr scuffproof in flat.

The building has a flat roof also so the attic units would not look much different than the lower units.

It's a flat roof so not a lot of space up there but enough for the racoon.I'm going to ask him his plans to repair but if he doesn't want to, what would you do?