COVID-19 has caused global dramatic change in medical practices including the introduction of temporary screening and assessment areas outside the footprint of the main hospital structures. Following the initial surge of patients with novel coronavirus (2019-nCoV) in the United States, our medical center rapidly designed and constructed an alternative assessment and treatment site in a converted parking garage deck for emergency department patients with suspected or confirmed 2019-nCoV. During the first month after opening, 651 patients were treated in this alternative assessment area including 54 patients who tested positive for 2019-nCoV. This accounted for 55% of the 98 patients with confirmed novel coronavirus (2019-nCoV) who were treated in our ED. This report provides a blueprint for the necessary steps, materials, labor needs and barriers, both anticipated and unanticipated, to rapidly construct an alternative ED treatment site during a pandemic.