An existing 900-square-foot, one-story cottage with a partial walk-out basement on Lake Sara in Effingham County, Illinois, was transformed into a new 3,500-square-foot, year-round lake house. The expanded residence includes two kitchens, living, dining and family rooms, along with 5 bedrooms, 3 full baths, 2 half baths, a three-car garage and a boathouse. The home sits on an acre of land with over 100 feet of lake frontage.