Nearly 400 volunteers are participating in Greater Des Moines Habitat for Humanity’s Blitz Build this week in the organization’s Carter Court development near Northeast 46th Street and Hubbell Avenue. The volunteers are putting up the walls and roof trusses for eight affordable houses. The Blitz Build runs through Friday. Participants include employees of corporate partners, community members and future homeowners. The nonprofit recently began construction of its 500th affordable home in the development.