Complex sentence: From 1992 to 1994, the entire Aon Center was reclad in white granite, and in 2009, it was announced that First Canadain Place would have its marble curtain wall replaced with white ceramic fritted glass panels.
Split into simpler sentences: From 1992 to 1994, the entire Aon Center was reclad in white granite. In 2009, it was announced that First Canadian Place would have its marble curtain wall replaced with white ceramic fritted glass panels.