Our project consists of adding a new 5,000 square foot education building addition to an existing 17,500 square foot education building. The original building was not submitted for LEED certification but we are submitting for LEED certification on the new addition. The original project was constructed with a complete four pipe hydronic system including chillers, pumps, and boilers that have the capacity to handle the new addition with no added plant capacity. The scope of this project is to provide new air handling equipment and extend the existing four pipe hydronic distribution system to the new air handling equipment. Our approach to satisfying the newly established mandatory 14% energy efficiency improvement is outlined as follows: A base case model was established by using the criteria set by ASHRAE Standard 90.1-2004, Energy Standard for Buildings except Low Rise Residential Buildings. The minimum requirements established for this model are as follows: -Walls: Mass Assembly with U-value = 0.58 Btu/hr.ft2-
In requesting clarification on the proposed modeling methodology, it is unclear, based on the information provided, whether the project team is modeling the existing building as well as the addition. From ASHRAE Table G3.1 #2, the project will not meet all of the conditions to exclude parts of the existing building, as the requirements of (b) are not satisfied. Therefore, the project team must model the entire building, taking care to follow the requirements of Table G3.1. This includes #5, where the existing envelope must be modeled equally for the proposed and baseline cases, as well as the HVAC Systems requirements in #10. Please note that #10 portion (a) states that when an existing HVAC system exists, the proposed model shall reflect the actual system type, etc.