The Big Build, on Oct. 14 from 10 a.m. to 4 p.m. at the National Building Museum, 401 F St. NW, is an interactive, fun-for-all-ages celebration of our built environment. Learn from construction and building arts professionals while hammering nails, sawing logs, applying join compound, and hopping aboard real trucks. Each year at The Big Build, amateur builders can discover what it’s like to build a brick wall, carve stone, hammer nails working side-by-side with designers, builders and artisans. Meet plumbers, ironworkers, landscape architects, woodworkers and experts in many other fields to learn about their professions and hobbies. Admission is free. Recommended for ages five through twelve. nbm.org.