The primary goal of this low-energy retrofit was to develop an exterior wall assembly that would improve the building performance and energy efficiency of an existing residence in Sewickley, Pennsylvania. Energy modelling software was used to analyze heat and moisture transfer, hygrothermal behavior and eliminate the potential for mold growth. This data was then used to evaluate the best option for design, budget, and performance. This project emphasizes our firm's commitment to the purpose beyond the occupation - wanting to see our architectural work return value to the client and improve the quality of life for a building's occupants. The renovated home itself is now “giving back” to its owners through reduced energy costs, increased thermal comfort, improved acoustics, and an enhanced aesthetic design.