屋根を取り換えないといけないかも…　この家も古くなってきてるからなあ。
We might have to replace the roof.　This house is getting old.

　この家、どのくらい古いの？
How old is this house?

　少なくとも40年は経ってるな。パパよりも年上なんだぞ！
I'd say it's at least forty years old. / I'd say (that) at least forty years have passed.　This house is even older than I am!