Historic preservation projects require a significant amount of care and attention to detail. Although window replacements are traditionally seen as a last resort to repair and ongoing maintenance, working with the right partners can improve the building’s energy efficiency while preserving its legacy. Windows can have the most significant architectural impact on a building’s aesthetics, and architects and designers should understand how to balance the needs of multiple stakeholders. This is achieved through knowledge of windows’ role in both sustainability and preservation, increased building operational efficiency, various design options to meet strict historic renovation criteria, and how to manage federal, state, and local building codes and tax incentives.