Building Energy Codes and Requirements

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	Cool Roofing: A Solution to National Energy and Environmental Challenges Self-guided presentation (HSW and SD credits). A detailed overview of the performance characteristics and benefits of cool roofing systems using reflective white vinyl roofing. Green roofing, energy saving programs, environmental challenges and solutions are also reviewed. For instant access to the course, click here »

REFLECTIVE ROOFS
GREEN (PLANTED) ROOFS
COOL ROOFING CODES, PROGRAMS AND STANDARDS
BUILDING ENERGY CODES AND REQUIREMENTS
PRODUCT RATING PROGRAMS
GREEN BUILDING AND SUSTAINABILITY STANDARDS
VOLUNTARY GREEN BUILDING PROGRAMS
ENERGY SAVING CALCULATORS

BUILDING ENERGY CODES

State of California Title 24: California Code of Regulations

California’s building energy code prescribes a cool roof for many low slope, non-residential applications. Qualifying roofs must be tested by a Cool Roof Rating Council approval laboratory and receive a CRRC label, be over conditioned space, and have a slope of less than 2:12. Initial thermal emittance must be 0.75 or greater and initial solar reflectance must be 0.70 or greater.

Title 24 Changes Now In Effect
In January, updates to California’s Title 24 Energy Code became effective. For the first time, aged values for solar reflectance will be used for products registered with Cool Roof Rating Council. Enforcement will occur according to climate zones, and a solar reflective index (SRI) is now an alternative to meeting separate solar reflectance and emittance requirements. Review the regulations here:

Title 24 2008 Building Energy Efficiency Standards: Nonresidential Compliance Manual » [538 KB PDF]

Envelope Component Approach
Complexity	Simplest
Flexibility	Least flexible
Tradeoffs	Does not allow tradeoffs - each building component must meet or exceed the requirement for that climate zone
Calculations	Fewest calculations
Cool roof requirement	Cool roof is required for low-sloped and steep sloped buildings
Overall Envelope TDV Energy Approach
Complexity	More complex
Flexibility	Somewhat flexible
Tradeoffs	Allows tradeoffs - if one building component does not meet the requirement but another exceeds it, it may offset the component that does not meet the requirement
Calculations	Requires more calculations
Cool roof requirement	Cool roof is not necessarily required
Whole Building Performance Approach
Complexity	Most complex
Flexibility	Most flexible
Tradeoffs	Allows tradeoffs - if one building component does not meet the requirement but another exceeds it, it may offset the component that does not meet the requirement
Calculations	Requires computer simulations
Cool roof requirement	Cool roof is not necessarily required

City of Chicago
Chicago requires cool roofs on low-slope buildings as part of its Energy Code (Chapter 18-13-101 of the Municipal Code of Chicago) to minimize the urban heat island effect. Generally, low slope roofs installed after April 22, 2009 on new structures and on buildings being re-roofed have an initial reflectance requirement of 0.72 or a 0.50 weathered reflectance value as determined by the Cool Roof Rating Council or ENERGY STAR. Where more than half of the total gross area of the roof is covered with an intensive or extensive green roof as defined by the U.S. EPA, the required reflectance value of the remainder of the roof is 0.30.
Chicago Energy Conservation Code »

U.S. Government
Federal Acquisition Regulation Case 1999-011 (formerly Executive Order #13123) requires federal office buildings (Department of Defense, General Services Administration and National Aeronautics and Space Administration) to reduce energy consumption 30 percent by 2005, and 35 percent by 2010; federal industrial labs 20 percent by 2005 and 25 percent by 2010. ENERGY STAR products must be used when available.
www.acquisition.gov/Far/

Under President Obama’s Executive Order on Sustainability, issued October 2009, the federal government is required to reduce its greenhouse gas emissions 28 percent by 2020.

As part of this initiative, on June 1, 2010, Secretary Steven Chu announced that all Department of Energy offices would be required to select cool roofs when undergoing roof construction projects or replacing old ones, unless deemed uneconomical by a life-cycle cost analysis.

Chu’s memo (complete download available here [396 KB PDF]) provides the following guidance for determining a cool roof:

To be considered cool, a low-sloped roof (pitch less than or equal to 2:12) must be designed and installed with a minimum 3-year aged solar reflectance of 0.55 and a minimum 3-year aged thermal emittance of .75 in accordance with the Cool Roof Rating Council program, or with a minimum 3-year aged solar reflectance index (SRI) of 64 in accordance with ASTM Standard E1980-01.

To further shed light on cool roofing for federal and commercial building operators planning on installing cool roofs, DOE released its Guidelines for Selecting Cool Roofs [804 KB PDF], which provides technical details on types of roofing materials and how to select the roof that will work best on a specific facility.