The project consists of four interconnected laboratory buildings as part of a university science complex in Allston MA. The buildings are new construction, with 5-7 story structures, primarily steel and concrete materials consisting of approximately 1,000,000 square feet. The Option 1 (Whole Building Energy Simulation) for this credit requires a demonstration of a percentage improvement in the proposed building energy performance compared to the baseline energy performance found in ASHRAE 90.1 - 2004 Appendix G. The baseline modeling requirements of the ASHRAE 90.1 system are appropriate for office buildings but the unique characteristics of a lab create certain conflicts with the ASHRAE 90.1 system. They are as follows: - While the standard provides pressure credits for filtering systems, heat recovery, etc., laboratory fan systems typically exceed the fan limitations even with these credits due to other components. - Conflicts with minimum airflow in standard and laboratory minimum ventilation rates both occupied and unoccupied. - Schedules of equipment operation are different than in the ASHRAE baseline. - Additional conflicts with the application of the standard to labs are identified in the Labs21 modeling guidelines. Proposed Modeling Strategy The design team is proposing the use of "Laboratory Modeling Guidelines using ASHRAE 90.1-2004 Appendix G" produced by Laboratories for the 21st Century, or Labs21. A joint venture of the Environmental Protection Agency and the Department of Energy, Labs21 has enlisted some of the biggest laboratory operators in an effort to corral energy consumption and cut attendant costs. Participating labs are saving up to 30-50 percent on their energy bills compared with those not using the program. The guideline describes an appropriate baseline model for energy benchmark simulations using ASHRAE 90.1-2004 including proposed corrections (http://www.labs21century.gov/pdf/ashrae_appg_draft_508.pdf). Although proposed use of this standard was previously not accepted by the USGBC in the CIR dated 5/11/2005, the USGBC\'s LEED for Laboratories Application Guide (Draft) clearly acknowledges the issues with the ASHRAE standard and therefore, under Requirement 1 for Energy and Atmosphere, states "the building project is to comply with.the requirements of the Labs21 Laboratory Modeling Guidelines using ASHRAE 90.1 - 2004." The various proposals of the Labs 21 Committee have been included in the continuous maintenance efforts of ASHRAE and modifications continue. Some of the revisions are under public review (addenda o and r) and some are already accepted addenda (e.g. addendum ac - fan power for laboratory type zones). Additionally, this standard has been approved by the State of Massachusetts for use as the base case. Per the memorandum published by the USGBC in April 26 2007, "LEED project teams are required to use the ASHRAE Standard referenced in the applicable Reference Guide and are permitted to use addenda within the most recent Supplement to that Standard, as well as any approved addenda published in between the eighteen-month periods." Request Please confirm that using the Labs21 "Laboratory Modeling Guidelines using ASHRAE 90.1-2004 Appendix G" is acceptable when recommendations of the Labs21 have not already been implemented by ASHRAE 90.1 energy modeling baseline. For all items covered in Labs21 that have been addressed by ASHRAE amendment, we will use the ASHRAE requirements.