Help with insurance claim for partial loss of use

[Lawrence Hsu]

In brief, I have a rented condo that was damaged due to an upstairs unit leaving their bathroom water on. Master bath/bdrm unusable (it's a 3 bdrm unit). Can argue up to 50% of the unit is not usable. Have a tenant who is reasonable and prefers to stay, but wants some partial rent abatement for loss of use. The unit is still partially habitable in the meantime. Tenant is currently on a month-to-month lease. My main question is getting a partial loss of use settlement from the insurance company. It's been 6 wks, and damage mitigation is done, but repairs not yet even started, so this will likely take a while.

There is an open liability claim for the at fault unit (they have a renter's policy) that I've been dealing with who have been putting up a fight. They will not even give a guarantee of partial loss of use payment until all repairs are complete. It's understood an exact amount can't be calculated until the duration of repairs are known. However, they won't even give a guarantee there will be payment, nor even estimate a percentage loss of use in the meantime (there is enough information available to at least make this determination). The issue is I'd like to give my tenant some certainty he'll get an abatement, since this affects his decision to stay or leave.

Using my own policy is not an option. I only have 1k loss of use coverage (not enough), and it only kicks in if I have to put them up in a hotel. I'd also prefer not to have a claim on record. My tenant's renters policy states the same. 

Questions:

1) Is this standard for insurance companies to make no guarantee of payment until everything is all done? Understood an exact amount can't be calculated, but it's pretty easy in this case to at least guarantee a percentage loss of use in advance. Is there a strong chance they'll simply reject my claim? I'm not sure how insurance companies determine loss of use in this situation.

2) Any other advice how to handle this? Have filed a complain with insurance board.

Any advice is appreciated!!