We have a tenant renovation project within existing building. Currently the tenant space does not have air conditioning system and is naturally ventilated. As part of the renovation the tenant is planing to add series of external shading devices to improve the comfort withing the tenant space and enhance the natural ventilation strategies that the existing space already has. The existing space has what appears to be well thought strategies for cross ventilation through operable window and operable ventilation openings with louvers and open floor plans with internal atrium enhancing the natural ventilation flow paths. The question is if there is any way we can take credit and get points under EAc1.3 for not providing AC? Any ideas how we can document such energy savings are welcome. As an idea, we can try to use energy simulation software such as Energy Plus or Design Builder which have capabilities to simulating natural ventilation and indoor conditions due to the natural ventilation and external shading strategy. We hope to be able to show that such conditions are in accordance with the thermal comfort requirements of ASHRAE 55 Section 5.3. On a separate model we can then run baseline with AC per ASHRAE 90.1 and proposed as designed and without AC, while both models use the same thermostat setpoints equal to the one from the natural ventilation simulation, Looking at the ASHRAE 55, for the mean monthly outdoor temperatures we have in our climate we can maintain up to 80 deg.F indoor temperature and it would be considered within 90% acceptable limits! However, this method is a bit complicated and may be cost prohibitive for the about 3000 sq.ft. tenant space project we have. Any ideas and/or previous experience with similar documentation approach and requirements are appreciated.