The Gwinnett Environmental and Heritage Center will host its fourth annual Sustainable Gingerbread House Competition and Exhibit the week of Thanksgiving. Designers are asked to create environmentally friendly houses highlighting sustainability and green building design using edible materials. “This is a great opportunity for families, businesses, civic groups, students and/or individuals to get into the holiday spirit and show off their gingerbread building talents and green building ingenuity,” GEHC program director Jason West said.