The aluminum and limestone façade of this forty one story high rise building overlooking Chicago’s Millennium Park was exposed to urban pollution and weathering for more than 25 years without a comprehensive cleaning. Although the limestone has been repaired over time the aluminum components of the façade were not specifically addressed. The structural integrity of the aluminum surfaces was not compromised however the long term weathering adversely affected the appearance of the once metallic finish. Each window frame and spandrel panel will be detailed by hand utilizing abrasive cleaning methods to restore the aluminum to its intended appearance then sealed with the Alumitec wipe-on sealer to protect the finish and restore its metallic sheen. The resulting improvement in appearance will be dramatic and add significant value to this proud Chicago icon. At the request of the building owner the bottom ten floors of the south elevation will be cleaned first. We will then move back to the top floor and work from top to bottom. Creating broad columns of restored metal. The south and west elevations will be cleaned in 2013 followed by the north and east elevations in 2014.