I have a friend whose priest comes around once a year and blesses all the parishioners homes. When she told me about it, I said, "My house doesn't need to be blessed - it needs an exorcism!"
Why do you think that way, debodun? We did have our house blessed before moving in which is more the usual timing. I suppose it's more for starting fresh without any remaining essences of the previous occupants. Same goes for a good cleaning, etc.
But why an annual blessing except for certain circumstances that maybe folks believe they require it?
It overlooks the Hudson River in places. This is the view across the street. I am up on a knoll, so even if the river floods, which it did about 20 years ago, I'm up high enough not to be effected.