With DD we did for a few minutes at 7, up to an hour a couple times a week at 8. At 9 she became a bit more tentative and fearful, so she rarely stayed home alone, and then only for an hour or less. By 10 she was ready to do more, so she started staying home alone for 2-3 hours several times a month. At 11, she can now occasionally stay home alone all day, and comes home from school to an empty house at least once a week.