A Case Study of Early Steel Curtain Wall Dec, 2005 By Eric Hammarberg, Assoc. AIA In Feature This article is currently only available in PDF format, please click the link to the top right. About the author ⁄ Eric Hammarberg, Assoc. AIAEric Hammarberg, Assoc. AIA, is the Director of Preservation and a Vice President with Thornton-Tomasetti Group, LZA Technology Division in New York. Prev Excellence in Structural Engineering Next Micropiles