The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project is the development of energy efficient building coatings that have the potential to significantly reduce greenhouse gas emissions. The market for energy efficient coatings is experiencing accelerated growth due to government and rapid rise in demand for Leadership in Energy and Environmental Design certified structures. With these recent developments, building developers are actively seeking solutions which are technologically robust and cost-effective for meeting energy mandates. These novel architectural coatings not only provide the aesthetics and textured finish as traditional architectural coatings, but also provide the added benefit of decreasing heating and cooling related costs for the building owner.This Small Business Innovation Research (SBIR) Phase I project is focused on developing an optimized blend of phase change materials for incorporation in architectural building envelope coatings such as paint, plaster and stucco, to provide them with insulative properties. The optimized blend will consist of phase change materials (PCMs) with different phase transition temperatures in specific volume proportions to maximize energy savings in a specific climate zone in terms of heating and cooling costs. Preliminary lab work has shown promise that PCMs can be utilized in coatings to reduce temperature swings and shift the peak load to off-peak hours, which can lead to significant cost savings. This project will develop protocols to maximize incorporation of PCMs in these coatings without compromising their aesthetics. Energy modeling and experimental work including micro- and macro- scale material characterization will be carried out to verify the laboratory and small field-scale performance of these coatings.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.