Building energy codes, which set standards for the energy efficiency of residential and commercial buildings, are one of the most significant components of energy policy in United States. Building codes typically allow builders to comply with a code via a performance-based compliance path that determines compliance by evaluating the projected energy expenditures associated with the building's design. In essence, performance-based codes determine compliance based on private utility bill savings. In this paper, I demonstrate that energy codes would be improved if compliance was instead determined by the projected social damages associated with a building's design. Damage-based codes would provide incentives for conservation across energy types (electricity, natural gas, fuel oil) that better match the regional energy portfolio. Additionally, I demonstrate that damage-based codes that were primarily motivated by carbon mitigation would typically place greater emphasis on conservation of electricity, and less emphasis on conservation of natural gas in most states. Damage-based codes would likely lead to substantial welfare gains.