Rating System

LEED BD+C: Core and Shell

Rating System Version

v2 - LEED 2.0

Inquiry

Appeal for Ruling on LEED CS CIR for credit EAc1 dated 2/11/08 CIR: The PERCENT energy cost savings for EAc1 is based solely on Core & Shell components. Reviewer response: The request "significantly modified the approved calculation methodology." "The methodology published in the LEED-CS v2.0 Reference Guide was balloted and approved by the USGBC members and cannot be modified via a CIR." Appeal: A. The CIR proposes to clarify, not modify, a calculation method. B. The Reference Guide supports the proposed interpretation of the calculation method C. This interpretation is consistent with the other LEED CS credits. A. LEED-CS RATING SYSTEM, APPENDIX 2 IS UNCLEAR ON THE CALCULATION PROCEDURE FOR EAc1. THE RATING SYSTEM INTENT SUGGESTS THE USE OF ONLY CORE & SHELL ENERGY. ITEM 1.1: Projects must use ASHRAE 90.1-2004 Building Performance Rating Method. This requires that all loads, including tenant loads, be modeled. It does not indicate whether tenant energy is included in the percentage calculations. ITEM 1.2: Tenant spaces are defined by energy using components paid for, metered and apportioned, or billed to, the tenant. ITEM 1.3: "Thus, the scope of a LEED CS project is limited to those aspects of the project over which the developer has direct control." ITEM 5: The energy cost of the Budget and Design buildings determine the percentage savings. We contend that Items 1.2 and 1.3 should decide whether the annual costs are of the ENTIRE building or of CORE & SHELL. B. LEED-CS REFERENCE GUIDE, APPENDIX "CORE & SHELL ENERGY MODELING GUIDELINES" CLEARLY DIFFERENTIATES BETWEEN CORE & SHELL VS. TENANT ENERGY USE. IMPLICATION: UTILIZE CORE & SHELL ENERGY USE FOR THE EAc1 PERCENTAGE CALCULATION. The percent energy cost savings is calculated as follows: a. MODEL THE ENTIRE BUILDING, including Core & Shell areas AND Tenant Fitout areas NOTE: This procedure is not disputed. b. TRACK SEPARATELY the energy use of Core & Shell vs. Tenant Fitout. NOTE: See 2.2.1.1 and 3.2.1.1. "Model SEPARATE electric meters for the lighting in the core." See 2.2.2.1 and 3.2.2.1 "Model SEPARATE meters for tenant plug loads and process loads." This signals the intent to use ONLY Core & Shell costs for the percentage calculation. c. SIMULATE, THEN CALCULATE the percentage energy cost savings, using Steps 4 and 5. NOTE: Step 5.1 references the "budget building" and the "design building." It does not say whether these models are just for CORE & SHELL or the ENTIRE building. However, under "2. Proposed Building Model" (term used interchangeably with "Design Building") the proposed building is listed as "2.1 Core & Shell Building." Same for "2. Baseline Building Model." When Step 5.1 refers to the "annual costs of the budget building and design building," it is consistent to assume that, per Step 2, "building" means "Core & Shell building." Finally, Step 5.3 does not indicate whether the calculation is done using only Core & Shell energy cost, as we believe is the intent of the document, or using the energy cost of the entire building. We contend that this was an editorial oversight. C. ONLY THE PROPOSED APPROACH IS CONSISTENT WITH THE OTHER LEED CS CREDITS Tenant fit-out is not included in the calculation of percentages for: EAc6 Green Power WEc3 Water Use Reduction MRc2, Construction Waste Management MRc3, Materials Reuse MRc4 Recycled Content MRc5, Regional Materials MRc6, Certified Wood EQc4.1-4.4, Low-Emitting Materials EAC2 Renewable Energy references the energy use of the entire building. The percentage savings for CS is 1% vs. 2.5% for NC. For EAc1 the percentages of CS and NC are identical, indicating that the CS calculation refers to Core & Shell energy only.