A Regional Green Building Case Study Project

This report from the U.S. Green Building Council's Chicago Chapter is the first to provide detailed post-occupancy performance data on a regional level.

The study looks at 25 LEED-certified buildings in the Chicago area and reports on energy and water efficiency, greenhouse gas emissions, occupant comfort, and other performance indicators.

From the introduction to the report:

While this project is neither the first nor the largest study to analyze the costs and benefits, or post‐occupancy energy performance of LEED projects, this study is unique both in its scope and collaborative approach. This project is one of the first post‐occupancy studies to employ such a broad scope of metrics. It is also among the first to collect multiple years of post‐occupancy data and provide ongoing analysis of initial participants while adding additional projects in subsequent years. The project employed a stakeholder engagement model based on regional partnerships, and a valuable back and forth dialog with project stakeholders. This dialog included preparing detailed individual building performance reports for each participating project and follow up meetings with project stakeholders so that project representatives could better understand their buildings’ actual performance.

The measured performance results of these 25 Illinois LEED projects are a snapshot in time of these specific projects. Extrapolating the results from this data set to represent the performance of all LEED projects in Illinois, or all LEED projects in general, is not valid. It is expected that another set of participants will yield different results because of the mix of unique buildings and building activities. It is also quite likely that the performance of these same projects will change over time due to occupancy, operations, maintenance, and systems changes.