It was March of 2001 when Chicago Mayor Richard M. Daley introduced “an energy code for Chicago that promotes efficiency and protects the environment.” Part of the code set forth requirements for new roofing systems and repair and replacement of existing systems relating to insulation and reflectivity. The code in its original form virtually eliminated most of the most common low-slope roofing systems that were being specified and installed at that time.
The Chicago 2001 energy code set off alarms all over the industry as the emerging “cool roofing” movement was just getting legs. This initiative set many conventional low-slope systems on their ears, at least in Chicago. It was a problem, however, that extended beyond the borders of the Windy City. Chicago was on the leading edge of a movement that was spreading all over the country. The movement that brought about changes to the city of Chicago’s building code in 2001 has shaped many changes in the low-slope roofing industry over the course of this decade.
Following years of study, including the study by Oak Ridge National Laboratory for the Single Ply Roofing Industry (SPRI) titled “Evaluating the Energy Performance of Ballasted Roof Systems” and lobbying efforts by various industry groups, the City of Chicago recently published new standards for new and existing low-slope roofs. The new standards, taken from the city of Chicago Building Code, Chapter 18-13 - Energy Conservation, allow (as an exception to the rule requiring an initial reflectance value of 0.72 or a three-year installed reflectance of 0.50 as determined by the Cool Roof Rating Council or Energy Star) that ballasted roofs “with a minimum of 15 lbs/sq. ft. of ballast over the entire roof surface may have a reflectance value of a minimum of 0.30.” There is also an exception relating to the replacement of a ballasted roof with a ballasted roof and an exception for replacing low-slope roofs with a built-up roof, allowing the same minimum reflectance of 0.30 for the top layer of aggregate.
According to news released by the EPDM Roofing Association (ERA), there are several other state and national standards that have adopted and/or tentatively initiated similar standards to the changes put forward in the city of Chicago building code.
Since the city of Chicago is recognized nationwide as a leader in the area of urban heat island mitigation and building efficiency and sustainability through its roofing code, other building interests pay attention to the Chicago code. On balance, the initiative begun in 2001 has been a good thing for the roofing industry as it highlights the importance of the roofing system in terms of building sustainability and efficiency.
The problem with the original code was it did not take all building systems and their unique roofing needs into consideration. The exceptions they recently published give back the kind of flexibility roofing contractors and building designers need to come up with the best overall solution to building thermal and moisture protection. It is good not only for the city of Chicago but for others who seek to emulate their efforts to enact codes that are considered as most sustainable and friendly to the environment. And ballasted EPDM or aggregate-surfaced BUR systems are among those most time-tested and proven low-slope systems on the planet.