The aim of this study was to develop, refine, and assess the usability of pictorial action instructions (PAI) in training low-literacy individuals to build a basic humanitarian engineering project. Health in low- and middle-income countries is disproportionately affected by environmental hazards, often mitigated by such projects, but widespread literacy deficits often necessitate literacy-adapted materials for training. Project-specific PAI were developed, refined, and tested, with the intent of later testing them abroad. Development was based on best practice guidelines for illustrations and easy-to-understand text. The PAI were then reviewed by literacy specialists for content and formatting. Next, a feasibility study was conducted in Utah with low-literacy immigrants who were trained to use the PAI and provided with tools and materials to individually construct the project. Usability metrics gathered included construction efficiency and effectiveness, user satisfaction, and self-efficacy. Effectiveness was 100% and user satisfaction and self-efficacy were both high. Participants provided feedback to improve the PAI’s clarity by changing item proximity and combining or separating steps, and revisions were made. In future PAI development, it would be beneficial to include low-literacy individuals when making the initial sketches to enhance sequence clarity before finalizing the illustrations.