Key Findings from the DEP Green & Energy Efficient Roofs Research Report

At True Metal Supply, we believe in making informed decisions based on data. That’s why we’ve compiled a summary of the key findings from the Green and Energy Efficient Roofs Research report provided by the Florida Department of Environmental Protection (DEP). This collection of studies and articles provides a deep dive into the technologies that make modern roofing a cornerstone of sustainable building.

Florida DEP

Below is a technical overview of the report's most significant findings. For those interested in a more detailed analysis, a link to download the full report is provided at the end of this post.

Core Principles of Energy-Efficient Roofing

The report begins by distinguishing between energy efficiency and energy conservation¹. While conservation involves behavioral changes, energy efficiency is achieved through technology that allows a system to do the same work with less energy². The research highlights two primary heat-management strategies for roofing:

• Thermal Insulation: This method, employed by materials like fiberglass, functions by absorbing heat³. The report notes a key limitation: thermal insulation has a finite capacity and can become "saturated" with heat, after which it begins to pass heat into the living space⁴⁴⁴⁴.

  
  

• Radiant Barriers: In contrast, this technology reflects radiant heat away from the home instead of absorbing it⁵. A significant finding in the report is that radiant barriers have no capacity limits and can continuously reflect heat without any change in performance⁶.

Report Findings on Vegetated "Green" Roofs

The report includes data from a multi-year research project on a 1,600-square-foot "green roof" at the University of Central Florida⁷⁷⁷⁷. The monitored results showed substantial environmental benefits:

• The green roof was able to retain 80 percent of the average annual stormwater volume from the roof⁸.

  
  

• Energy monitoring identified significant savings, with the potential to save between

  18.8% and 43.3% in summer months as the roof matures⁹.

  
  

• When outside temperatures were below 55°F, the observed energy savings were about

  50%¹⁰.

  
  

Another study referenced in the report found that on a 91°F day, a traditional black-top roof surface reached

154°F, whereas vegetated roof surfaces were dramatically cooler¹¹.

Analysis of "Cool" Metal Roofing in the Report

For homeowners and builders focused on durability and energy performance, the report provides a compelling analysis of metal roofing systems. The research identifies several key technical merits:

• Superior Reflectivity: The report states that a metal roof with an EnergyStar finish is the most radiant-reflective roofing material available, bar none¹². It reflects the sun's energy rather than absorbing it, leading to a cooler roof and attic¹³.

  
  

• Lifecycle and Sustainability: Metal roofing is presented as a 100% recyclable product¹⁴. The research notes that new panels often contain up to 40% recycled steel and that the same panels can be fully recycled after their long service life¹⁵.

  
  

• Durability: The report highlights that modern metal panels are treated with advanced finishes like SMP (Siliconized Modified Polyesters) to withstand weather for up to 40 years¹⁶. It also finds that metal panels can outlast conventional roofs by as much as four times¹⁷.

  
  

Future Technologies Profiled in the Research

Looking ahead, the report discusses emerging technologies from the Department of Energy's Oak Ridge National Laboratory¹⁸. Researchers there are developing a prototype roof and attic system that uses phase change materials (PCMs) sandwiched between reflective surfaces¹⁹. This system was found to reduce attic temperatures by about

22 degrees Fahrenheit during a typical summer afternoon²⁰. The research also points to the development of infrared reflective materials that are dark in color yet reflect light as if they were white²¹.

This summary provides only a high-level overview of the extensive data within the Green and Energy Efficient Roofs Research report. We encourage you to download the full document to explore the findings in greater detail.

Read Full Florida DEP Report

If the report's analysis of metal roofing systems aligns with your project goals, contact the experts at True Metal Supply today. We can help you apply this proven technology to achieve superior energy efficiency and longevity.