If modern engineers devote careful attention to the environment of a project and study historical building techniques they can create more sustainable structures. Rammed-earth construction creates a thermal mass structure that cools the interior space during hot, dry summers and absorbs heat during cold winters. It is a historic building method dating back over 2,000 years, and the techniques of native practitioners offer suggestions as to how modern engineers can successfully apply the method. © 2013 American Society of Civil Engineers.