Cook County, Illinois has over 130 incorporated municipalities, the largest of which is the county seat, Chicago, which makes up approximately 54% of the population of the county. The county of 5,294,664 residents is the second most populous in the United States after Los Angeles County, and is home to 43.3% of Illinois residents. Cook is on the coast line of Lake Michigan and has a total area of 1,635 square miles, 946 of which is land and 689 of which is water.

Cook County’s Building Construction ordinance requires that all newly constructed City buildings and those scheduled for capital improvements be designed, built, and operated to meet the requirements for certification under the LEED Green Building Rating System, Version 2.0. The ordinance requires that the County refer to the most current version of LEED when beginning a new building construction permit project or renovation and anticipates the US Green Building Council to update LEED approximately every three years. Additionally, all City retrofit projects must meet the requirements for certification for LEED Existing Buildings. All buildings must obtain at least eight points in the LEED Energy and Atmosphere category, and all new construction and major renovation projects must incorporate bird-safe building materials and design features.