In December 2012, the U.S. Environmental Protection Agency released a report on infill construction trends in America’s largest metropolitan regions. The analysis focused on the 51 Metropolitan Statistical Areas (MSAs) with more than one million people and analyzed changes in residential development patterns between two time periods (2000 to 2004 and 2005 to 2009). The report noted that, overall, the country has maintained its proportion of residential development occurring in infill areas and that the majority of new residential construction still occurs in greenfield areas. However, the analysis also indicated that regions with more miles of rail transit per person tend to have higher shares of infill development, as do regions with more transit ridership per capita. The authors hypothesize that this may be associated with transit oriented development strategies employed in regions with rail transit and note the need for further analysis to understand this link.

Overall, the Chicago MSA ranked seventh nationally in the proportion of its development that is infill, with 41.1 percent of its development occurring in infill areas between 2000 and 2009. The Chicago MSA also increased its proportion of residential infill development over the time period. Its infill proportion was 40.2 percent between 2000 and 2004 and rose to 43.3 percent between 2005 and 2009.  GO TO 2040 encourages infill development in existing communities where infrastructure to support it is already available. The plan also recognizes that such reinvestment projects must be implemented in ways that respect local character, historic context, and other local priorities such as increasing access to green space.