We live in a planned unit development (townhouse) and neighbors have been warning us about leaks. 

@Lucas CarlI give one polite warning.

Warning, not all but most window units with both need a 220V outlet.  

But, remember you were warned.

I do agree with getting a judgement, which would be a warning to future landlords and may allow you to recover funds. 

If someone wants to apply for a property that already has an existing application on it, I warn the new applicant before they pay.I do not refund application fees.

But, even still - you don't have to wait a year, document, document, warnings, 3 day notices ad infinitum.  

If there are noisy parties and they're bothering other tenants or neighbors, for instance.I had to disinvite a young couple who had a few warnings about parties in their unit, and the last straw was when one of their guests decided to pee out the bathroom window - through the window screen - and that window was in the middle of a U-shaped building, with their apartment in the inside of the U, and the other tenants who had windows facing the crazy party called me appalled. 

A new steel door will run $300 - $500 depending on style and quality and installation should be less than $200.If it's a good tenant (pays on time, takes great care of the home, etc) then I would probably give them a warning about personal responsibility and care of the home and then replace the door at my expense.

The economy is being pumped full of adrenalin right now, so we must be prepared for a drop of, and a huge one at that.winter is comingI've been warning people from the beginning.