Water gets the top of the list, twice. An active supply-line leak ruins cabinets, subfloor, and the unit below at a few hundred dollars a day — the $250 fix becomes a five-figure remediation in a wet weekend. And a 'minor' roof leak never stays minor: water travels, insulation holds it, and mold doesn't announce itself until drywall comes down.

Number three is anything electrical that trips, buzzes, or warms a faceplate. That's not an annoyance, it's a fire precursor — and it's also the cheapest of the five to diagnose early. Four is the water heater past its stated life: it fails as a flood, almost always on a holiday, and emergency replacement costs double the planned one.

Five is HVAC limping through the season it's needed most. Running a dying compressor through July doesn't defer the replacement, it just adds an emergency premium and a tenant who's pricing other apartments while they sweat.

The pattern: deferral doesn't pause the cost, it compounds it. Set dispatch rules so these five categories auto-route to your bench the moment a tenant reports them — speed here isn't a luxury, it's the discount.