Annual Expenses for a SFH you keep in your head.

[Andrew George Dennis]

This may be too wide a question, but just wondering: for those who purchase SFH's in stable, linear markets, what would be the average annual expenses you see on a long term buy and hold property. I'm talking like 1500 square feet with a yard, 3 bedroom 2 bath. I'm trying to wrap my head around it. The 50% rule doesn't work so well on this one rental house I have because it brings in about $1400/month. However, I'm thinking about repairs that may come down the road such as new paint, roof, furnace etc. How much should be saved annually for these items?