The original house (left) was in fair shape, but an energy hog.  We intended to keep most of the exterior, but the central masonry fireplace severely restricted layout changes. Extensive remodeling of older homes can be expensive, and make it difficult to meet energy, water, and structural standards. Most people simply smash up the old house and send it to the landfill, as was done to this house (below) in our neighborhood.
We didn't do this.