I think the main weakness in this business model, which is the same one with condos, is that people don't like to think about the really expensive things that they don't need to pay for regularly. When you need a new furnace/roof/fence/siding/driveway/etc., it's a multiple-$K hit. If you haven't budgeted for it (and I think most people don't), then the tendency will be to put it off for another year or three. I would guess the regular maintenance you outline takes care of perhaps only half the larger long-term upkeep problem. So prompt comprehensive maintenance with a flat monthly rate requires what seem like very high rates and some escrow, and also involves lower margins than it may appear to the customer. You may also become a magnet for customers who have already accrued a lot of "maintenance debt". So maybe you'd just need a long list of major unpredictable maintenance exclusions? Would that still be a satisfactory value proposition?