If you can concretly tie increased usage to that unit, I would give a notice that rent is increasing due to excessive use.

Looks like a bunch of concrete rubble or something.

Maybe save some cashola in the polish of the place.In the end, getting started isn't a easy row to hoe.

I sold a beachfront home last year that was ICF constructed in 2000 with a metal roof on concrete pilings and the insurance went up triple what my larger 2019 stick built with shingle roof 6 lots down is. 

The onsite-manager’s unit had a concrete floor which sometimes got wet from water coming over the sill in big storms.

According to the IRS guidelines, mobile homes set on concrete blocks and that are always capable of being moved from their sites on their own wheels are considered personal property (5 year).  

Same for a collapsed sewer pipe - they won't pay for the repair to the pipe, but they do need to pay for the damages caused to access that pipe like removing flooring, drywall, concrete, etc.

But if either 1) the line is very shallow, only a few feet deep and thus not a lot of digging is required, 2) the line is very long, like over 100 feet, and so it actually is substantially more expensive to replace the whole thing or 3) if the break is under dirt but the line goes under the driveway or a large amount of concrete.

Plus, keep an eye on emerging markets like Greenville and Columbia in South Carolina—they’re seeing more development and interest.I can get you more information on specific areas once you have a more concrete idea of where you want to invest.Let me know if you want to connect and I'll be happy to help. 

If the seller is still on the property after you close (you negotiated delayed possession), I wouldn't be opposed to doing exterior work (roof, landscaping, concrete, etc.), but I wouldn't do any interior work.