A comparison of California Title 24 Standards 2001 and ASRHAE 90.1 Standards1999 was conducted by Architectural Energy Corporation. The study used a sample size of 940 various nonresidential building types from the Nonresidential New Construction Database and modeled the buildings as built, with minimum compliance with the Title 24 Standard and with minimum compliance with the ASHRAE 90.1 Standard. |
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| By modeling the database above, Architectural Energy Corporation was able to determine the percent savings between Title 24 and ASRAE 90.1. A newer study between the Title 24 Standards 2005 and ASHRAE 90.1 2004 has not been completed. The following table demonstrates the bottom line comparison between the two standards. For example, to be 20% better than ASHRAE is equivalent to be 8% better than Title 24. |
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| The following graph compares the distribution of percent savings between Title 24 and ASHRAE 90.1. On the percent savings to energy code, the left of the zero (negative percent savings) represents non-compliance whereas the right of the zero (positive percent savings) represents compliance. The gray line represents Title 24 and the black line represents ASHRAE 90.1 for the same building. |
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| The United States Green Building Council (USGBC) also reviewed the data and determined its own interpretation for LEED compliance with the Title 24 Standard and the ASHRAE 90.1 Standard. For the Title 24 2001 Standards, one can take the Title 24 calculations and add 10% to determine LEED compliance. |
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