The Gwinnett Environmental and Heritage Center plans to celebrate STEM (science – technology – engineering – math) with a Build It Green event highlighting the sustainable features of its own building. Build it Green will take place from 10 a.m. to 4 p.m. Monday at the GEHC. Fees are $5 for ages 13 and older, $3 for ages 3 to 12 and free for children 2 and younger and GEHC members. The GEHC was the first LEED (Leadership in Energy and Environmental Design) certified building in Gwinnett County.