This paper presents a design proposal of an Isolation Recovery House (IRH), an adaptable modular isolation care unit specifically designed for patients with mild-to-moderate conditions as a response to an infectious disease outbreak. In particular, the study responds to the current COVID-19 pandemic, which urges the installation of isolation facilities as quickly as possible. The study offers a design solution that could expand the capacity for isolation facilities, especially in underdeveloped or developing countries, such as Indonesia, with many regions located further away from big cities. The design proposal assists existing hospitals in reducing excessive workload due to the surge in patients and control possible in-hospital transmission. The study began by investigating criteria for designing and constructing quickly-built isolation facilities that comply with the standards for isolation space, particularly COVID-19 patients. The criteria, namely quick construction, adaptability to various contexts, and meets the minimum isolation space design standards, formed the basis for proposing the IRH design. This paper argues that as a ready-toimplement design, IRH could be an option to improve health-care services during the pandemic.