The Mohalla (community) clinic scheme serves as the ‘first line of defence’ in Delhi’s primary healthcare system. Having evolved from the successful model of mobile vans or mobile medical units Mohalla Clinics (MCs) were developed to deliver accessible, high-quality, primary healthcare services to underserved communities at their doorsteps. The MCs are based on a zero-cost model where patients are provided with free consultations, drugs, diagnostics and pathological tests. Each MC is strategically located so that it caters to approximately 10,000 ~ 15,000 people who reside within a 15-min walk of the clinic. Launched in 2015, the MC scheme has expanded to 533 clinics today which cater to 16.24 million people annually. During the COVID-19 pandemic, when hospitals in Delhi had ceased to provide outpatient consulting services, MCs played a critical role as access points for people to receive primary healthcare services, as well as provide COVID-19 testing services. However, the COVID-19 pandemic revealed significant operational challenges for MCs due to spatial constraints and lack of adaptable features in the built environment. Therefore, this study used an ethnographic approach to observe how changes to the built environment of MCs necessitated by the COVID-19 pandemic influenced human-environment-interactions for healthcare staff. Observations were made at 24 MCs followed by semi-structured interviews with 35 healthcare staff. Thematic analysis of interview data revealed that the COVID-19 pandemic necessitated changes to the interior layouts of the clinics, healthcare services were offered through the building fenestrations and clinical workflow for healthcare staff was significantly altered. These modifications to the built environment and the workflow translated to changes in the human-environment-interactions for the healthcare staff. Consequently, quality of the staff-patient communication was negatively impacted and overall physical movement for staff had increased. Findings underline the need to develop flexible and resilient designs of MCs which focus on improving staff-patient communication and enhance the quality of healthcare delivery. Addressing the spatial design needs of healthcare staff in primary healthcare environments such as the MCs could improve future preparedness for pandemics, with implications for both staff satisfaction and healthcare delivery.