LEED Interpretation 1600 (see below for Interpretation language), which applies to EAc1, was written for LEED-CS version 2.0. The Interpretation website says that the ruling has not yet been considered for projects using LEED-NC 2009. Does anyone have success with applying this ruling to LEED-NC 2009?

Here's the ruling language: The project team is seeking clarification regarding the Baseline Building system type selection. The proposed design system is heated predominantly by electric resistance reheat controls, but includes some fossil fuel heating for morning warm-up and night-cycle control. Based on the size and number of floors for the building, the Baseline system type selection will be either System 3 (PSZ-AC) or System 4 (PSZ-HP). The functions described for the gas furnace appear to be consistent with the functions accomplished with a preheat coil. Per ASHRAE 90.1-2004 Section G3.1.2.3, if the HVAC system in the proposed design has a preheat coil, and a preheat coil can be modeled in the baseline system, the baseline system shall be modeled with a preheat coil controlled in the same manner as the proposed design. The ASHRAE User's Manual states "This means that adding a preheat coil is not something that can be credited toward a building performance rating." System 4 is a valid selection for the Baseline Building system, assuming that the project does not attempt to take credit for natural gas heating versus electric heating in the Proposed Building energy model. If the energy modeling software is incapable of modeling a gas furnace preheat coil for PSZ-HP systems, then the heating source would have to be labeled "Fossil/Electric Hybrid", and the Baseline system type would be System 3.