Rating System

LEED O+M: Existing Buildings

Rating System Version

v3 - LEED 2009, v3 - LEED 2008, v2 - LEED 2.0

Inquiry

We propose to satisfy this prerequisite requirement for an elementary school project utilizing the streamlined procedure provided in the LEED-EB Reference Guide. This would include developing and documenting a building energy baseline from historical energy use data for the existing school, and then documenting a reduction in annual energy use during the performance period of 10% or greater from the building energy use performance baseline. Additional Background: The original school was constructed in 1964. A design for renovation and additions was done in the late 1990\'s, based on the code requirements of the 1993 BOCA Building Code and associated energy code. Subsequent revisions of the ASHRAE 90.1 Energy Standard (1999, 2001 and 2004) have provided significant improvement in energy performance requirements. Taking these factors into consideration, the building energy performance for projects designed prior to implementation of ASHRAE Standard 90.1-1999 does not compare as favorably with buildings constructed to these updated standards. The building energy requirements enforced at the time of design also make it more difficult to achieve an ENERGY STAR Rating of at least 60. The proposed alternative of achieving a 10% or greater energy savings for a 78,000 square foot school could potentially result in reduced CO2 emissions of 200,000 lbs/year, and provide a significant environmental benefit. Is it acceptable to meet the Minimum Energy Performance Prerequisite by documenting a reduction in annual energy use during the performance period of 10% or greater from the building energy use performance baseline for projects designed prior to implementation of ASHRAE Standard 90.1-1999 Energy Standard for Buildings?