I stumbled across a “rule of thumb” that you should budget between 1 and 2% of your property’s value each year for maintaining it. That could be anything from getting the gutters cleared or roof tiles fixed, repainting a room, mending a fence etc.
AIBU to think that most people don’t spend anything like that much? For me that would be £4,500 per year. Nearly £400 every month just on maintaining it, not necessarily improving it.
(although that might explain why our house is currently a wreck!)