Energy Impact Illinois will hold an open house at 6:30 p.m. May 30 in the community room at the Jefferson Park Library, 5363 W. Lawrence Ave. Field organizer Bob Fuller will discuss how Chicago homes lose energy, which makes them less comfortable and more costly to heat and cool. The presentation also will feature the program benefits and examples of the 239 homes on Chicago’s Northwest Side that have utilized Energy Impact Illinois, including the home of Ald. John Arena.