Tom Boothby and Amanda Webb at Pennsylvania State University will use a 2015 PTT Grant to develop air flow and energy models for historic structures. Design decisions related to energy and indoor environmental quality may encompass the replacement of windows, the addition of wall insulation, and the addition or upgrading of mechanical systems. These decisions have both practical and philosophical implications for preservation. This project develops a comprehensive approach to the design of the indoor environment and its supporting mechanical systems in historic preservation practice. The approach applies statistical methods – uncertainty and sensitivity analysis, multi‐criteria decision analysis – to energy and airflow simulation models.