Typically, a building’s emissions are considered the outdoor emissions produced by constructing and powering that building. There is a growing movement to also address the emissions and harmful pollutants generated by the fossil-fueled appliances used within buildings. Limiting the outdoor emissions from appliances, such as nitrous oxides (NOx) and carbon monoxide, is an essential part of decarbonizing the built environment. One way state energy offices can reduce building emissions is to work with partners they may not have worked with before, state air regulators.