It's difficult to say with certainty how long Henry had lived in the house, because while we are told that he lived that "from his childhood up," we are not told whether his parents already lived in this house when he was born. Here's what we know for certain in terms of how long Henry has lived here: Henry was twenty-one when he married Phoebe Ann, and he was seventy when she died. They lived in this house for the duration of their marriage, which was forty-nine years. Henry had lived here with his parents for a number of years prior to that.
By the time Phoebe dies, he has certainly lived in this house long enough to be unable to think of considering anywhere else to be home. While suggestions were made that he go and stay with friends for a time, or seek out one of his surviving children, these ideas are of no interest to Henry. The only place he wants to be is home—the home he shared for so long with his beloved Phoebe.
Henry continues to live in this house for seven years after Phoebe's death, until his endless pursuit of her leads to his own death. Therefore, from the time of his marriage to Phoebe at the age of twenty-one to his own death at the age of seventy-seven, he lived in this house fifty-six years. It is also certain that for a large portion—if not all—of his first twenty-one years were lived in this house. Henry therefore lived in this house for somewhere between fifty-six and seventy-seven years.