Each month I pay council tax, water, gas, electricity and Internet. But randomly over the year I might pay insurance, garden maintenance, gutter cleaning, window washing, replacement of appliance that broke, repainting a wall I bashed moving furniture, etc etc.
1% of the value a year is a good guesstimate. I put about that value extra into my cash emergency fund and if the house needs a repair i can use that money.
You can keep costs down for a while if for example the boiler and appliances are new. Or you do gardening gardening window washing yourself. Or just buying a new build. But houses always break randomly and you can’t put off fixing that roof tile that slipped or that floorboard that cracked because after a while you have a more expensive problem to fix.