@Robert McNeal Thanks for the illuminating and civil discussion of a complex topic.

Not sure if she and her team does litigation but they are experts in securities law.Depending on the amount at dispute and underlying jurisdiction, you may also want to engage a large national firm.

End the accounting with the admonition of where they need to send the money they owe you.This will keep them from seeking out an attorney to litigate the matter. 

We actually fought a civil war over an unjust definition of "property".

First, vapor intrusion has become a leading source of litigation for personal injury and property damage claims.

In the worst case scenario, we can still go to court and file an eviction case and litigate to an eviction judgment. 

L. 96-605, sec. 102(a), 94 Stat. 3522, was ambiguous and caused excessive litigation, in 1984 Congress amended the statute.

Many will simply tell you that its a civil matter and to take it up in court (even if the guest really is trespassing). 

It will save you 6 months if headache and potentially some money .Option 1: Demo the house--> pay architect to design a new house --> Pay civil for foundation -> Pay city for new permit --> Wait 6 months --> get builder to build it Option 2: Pull rehab permit --> Demo the house to studs of foundation (keep something) --> have architect to design addition (exactly like new build) --> Pay city for permit <cheaper>--> wait 1 month while continue to work --> Use existing utilities --> use any contractor ... 

You can send bills but the reality is the majority of tenants don't pay them and it isn't worth the hassle to litigate.